Contents
- 1Introduction–A Collection of Heists
- 2The Murkmire Malevolence
- 3The Stygian Gambit
- 4Reach for the Stars
- 5Prisoner 13
- 6Tockworth's Clockworks
- 7Masterpiece Imbroglio
- 8Axe from the Grave
- 9Vidorant's Vault
- 10Shard of the Accursed
- 11Heart of Ashes
- 12Affair on the Concordant Express
- 13Party at Paliset Hall
- 14Fire and Darkness
- 15Credits
Affair on the Concordant Express
An Adventure for 9th-Level Characters
Wanted for crimes across the multiverse, an outlaw known as the Stranger is currently a prisoner aboard the Concordant Express, an interplanar train destined for Mechanus, where the outlaw is set to stand trial. In this heist, the characters must obtain a list of names the Stranger has committed to memory. The names in question are the true names of several powerful demons, devils, and yugoloths.
[image: The Concordant Express rockets through the Outlands on its way to Mechanus]
Adventure Background
The interplanar outlaw known as the Stranger had humble origins. The Stranger was born into a slum and orphaned as an infant. Early on, they used their knack for magic to masquerade as a lost noble scion and earn patronage as a spellcasting student. Inevitably, the school the Stranger was attending discovered the ruse, but the Stranger always slipped away and reemerged at an even more prominent academy in another city with a new false identity.
The Stranger perpetrated many crimes, none greater than the attempted theft of a book that held the true names of many demons, devils, and yugoloths (see "True Names" below). When the Stranger tried to flee with the book, a fiendish ward caused the book to disappear. By then, the Stranger had already committed many of the true names to memory. The Stranger then set off across the multiverse, making deals with various Fiends in exchange for keeping their true names secret. The Stranger survived all these dealings unscathed for years, but their luck eventually ran out.
Fiendish foes set their sights on the Stranger, forcing the Stranger to flee to the Material Plane and take refuge in the city-state of Akharin Sangar, which is ruled by a powerful angelic being. (Akharin Sangar is detailed further in Journeys through the Radiant Citadel). But the Stranger underestimated the vigilance of Akharin Sangar's celestial host and was caught impersonating an angel. When the Stranger refused to divulge any information about themself, a deva enforcer named Omid was tasked with delivering the Stranger to Mechanus to stand trial. The prisoner was clamped in dimensional shackles and taken aboard the Concordant Express for safe transport.
True Names
Every Fiend has a true name that it tries to keep secret. One who knows a Fiend's true name can use this name to bind that Fiend to service. Other powerful creatures such as Celestials and Fey might have true names that function similarly.
True names aren't restricted to spoken language or script. A creature's true name could be a specific gesture, sound, or other type of expression, such as the tolling of an iron bell, a mathematical equation, or a sequence of notes played on a particular kind of instrument.
Adventure Hooks
If you're using the Golden Vault as the hook for the adventure, skip ahead to the "x" section. Otherwise, choose one of the following adventure hooks.
Blood War Balance
A planar faction known as the Fixers aims to restore balance to the Blood War (the eternal feud between demons and devils) by obtaining the true names of a pit fiend commonly known as Karnyros, a balor called Errtok, and a marilith known as Hexalanthe. A representative of the Fixers hires the characters to obtain these Fiends' true names from the Stranger.
Fiendish Extortion
A high-ranking member of the Fated, a faction in Sigil, has been captured and is being ransomed by an ultroloth known as Zeevok. Faction leaders hire the characters to obtain Zeevok's true name so the Fated can force Zeevok to release his captive without collecting a ransom.
Personal Reasons
The characters seek the true name of a Fiend that has bedeviled them in the past.
Using the Golden Vault
If you're using the Golden Vault as a patron, a golden key is delivered to the characters in whatever manner you deem fit. When the characters use this key to open their music box, the lid pops open and a soothing voice says the following:
Closing the music box causes the golden key to vanish.
Glitch the Quadrone
Not long after agreeing to undertake the adventure, the characters encounter a friendly quadrone named Glitch. (When and where this happens is up to you.) The quadrone used to oversee hospitality on the Concordant Express. For this reason, it was imbued with the ability to speak Celestial, Common, and Infernal in addition to Modron.
Conflicting directives from two pentadrone superiors caused a glitch that prompted the confused quadrone to quit its job. Glitch has become a free-thinking being with no desire to reintegrate into the modron hierarchy.
Eager to help the characters, Glitch speaks to them in Common:
Glitch hands the characters an old blueprint of the Concordant Express (see x), one train ticket per character, and an ink pen. The tickets are made from paper-thin sheets of brass and grant passage to Mechanus aboard the Concordant Express. Each ticket is stamped with a boarding time, and the characters have 24 hours until the train departs.
Glitch takes the characters to the train when they're ready (see "x" below) and stays with them in the interim. Glitch also shares the following information:
- Configuration. Like most trains, the Concordant Express includes an Engine Car at the front and a Caboose at the back. The number of other train cars and their configuration can change, so Glitch can't say much more about the size of the train or the order in which the cars will be arranged. The configuration of the cars might be different than what's shown on the blueprint. (In fact, it is. See the "x" section for details.)
- Fuel. The train is fueled by treasure, which is kept in the Engine Car.
- Location of the Stranger. The Stranger is likely being held in the Jail Car, which has a skylight.
- Patrols. Modrons patrol the exterior of the train.
- Teleportation Ward. Creatures can't teleport into or out of the train.
The Concordant Express
The Concordant Express is a clockwork locomotive that traverses the multiverse. Modrons constructed the train with mathematical precision, and they operate it in the same way. The train's conductor is its sapient Engine Car, which delivers passengers and cargo to their intended destinations on schedule.
No terrain is too rugged for the train. Like the landmasses that make up Mechanus, the wheels of the Concordant Express are a network of interlacing cogs. A series of mechanical arms rapidly places levitating tracks before the train, while a similar set of arms beneath the Caboose collects the trailing tracks and delivers them to the Engine Car. This system allows the train to traverse inhospitable environments and to adjust course as needed.
[image: Map 11.1: Players' Map]
Train Configuration
The train has three mandatory cars and three optional cars, as described below.
Mandatory Cars
In this adventure, the Concordant Express has one of each of the following cars:
- The Caboose (x) is the rearmost car.
- The Engine Car (x) is the frontmost car.
- The train has one Jail Car (x), which is adjacent to the Engine Car (not the Caboose, as shown on map 11.1).
Optional Cars
x includes maps for six additional cars: Abacus Car (x), Aquarium Car (x), Cargo Car (x), Planartarium Car (x), Passenger Car (x), and Temple Car (x).
Pick any three of these cars and add them to the train in whatever configuration suits you, provided the mandatory cars stay where they are. (You can choose a different set of optional cars each time you run the adventure.)
You can add more than three optional cars to the train, at the risk of increasing the heist's length and difficulty. Conversely, you may opt for fewer cars for a shorter, easier heist.
Catching the Train
Embedded in Glitch's body is an amulet of the planes that turns to dust (along with the rest of the quadrone) if Glitch is reduced to 0 hit points. Glitch uses this built-in amulet to cast plane shift, delivering itself and the characters to a field in the Outlands (see the Dungeon Master's Guide for more information about this plane of existence). There they must wait for the train to arrive.
As the train approaches the characters' location, read the following text:
Glitch exits the adventure at this point, using its amulet of the planes to return whence it came.
Boarding the Train
The Caboose (x) doubles as a train station. Inside it is a booth containing a duodrone attendant with a built-in ticket puncher. All passengers must get their tickets punched by this duodrone before they're permitted to explore the rest of the train.
If one or more characters refuse to get their tickets punched, the duodrone whistles (no action required), causing four tridrones to emerge from hidden compartments in the walls and act as described in area E1. If the characters then comply to avoid an altercation, the tridrones return to their compartments.
Choo, Choo!
Once the characters' tickets are punched and the train is ready to go, read the following text:
General Features
The Concordant Express has the following features:
- Ceilings. Car ceilings are 15 feet high unless the text states otherwise.
- Doors. At each end of every car is a sliding metal door. The doors to the Jail Car are locked (see x for details); all others are unlocked.
- Flight. The train has a flying speed of 60 feet and can't hover.
- Lighting. All cars are brightly lit by magical orbs embedded in the ceilings.
- Modrons. All modrons serving aboard the Concordant Express speak no languages other than Modron unless the text states otherwise.
- Teleportation Ward. Creatures can't teleport into or out of the train, or to any space within 120 feet of it. Any attempt to do so is wasted.
Moving on the Train
To reach the Stranger, the characters must make their way from the Caboose (x) to the Jail Car (x).
Crossing between Cars
Creatures can safely move from one car to another by stepping across couplers situated between the cars' exterior platforms.
Falling off the Train
If an effect would result in a creature falling off the train, the creature must succeed on a DC 14 Dexterity saving throw. On a success, the creature instead falls prone in the nearest unoccupied space on the train. On a failure, the creature is sucked into the train's undercarriage, taking 33 (6d10) bludgeoning damage and landing prone in an unoccupied space at either end of the nearest train car.
If a character falls off the Caboose, the train's track-retrieval arms snatch up the character and deposit them into an empty cell in the Jail Car (x).
Guard Patrols
Hostile modrons patrol the rooftops of the cars, attacking anyone they see who isn't supposed to be there. Whenever one or more characters reach the midpoint of a rooftop on any car other than the Jail Car, roll a d6 and use the Guard Patrols table to determine if an encounter occurs. Assume the patrol begins the encounter on the rooftop of an adjoining car. All the modrons have truesight, and characters on the rooftop have nowhere to hide.
No random encounters occur on the roof of the Jail Car until after the squad of pentadrones stationed there is defeated (see x for details).
Guard Patrols
| d6 | Encounter |
|---|---|
| 1–3 | No encounter |
| 4–5 | Three tridrones and one quadrone leader |
| 6 | Four quadrones and one pentadrone leader |
Strong Winds
Creatures climbing on the outside the train or flying within 15 feet of it while it's in motion are subject to strong winds, the effects of which are as follows:
- Difficult Terrain. The wind-whipped exterior of the train is difficult terrain.
- Ranged Attacks. Ranged weapon attacks are made with disadvantage.
Planar Effects
The Concordant Express moves across the known planes of existence by passing through invisible portals only the train's sapient Engine Car can find. The train's next stop is Mechanus, but it will pass through several other Outer Planes on its way there. While the train shields passengers from the harmful planes through which it travels, creatures aboard the train aren't entirely immune to the planes' effects.
The Planar Effects table contains effects for various planes of existence on the train's current route. Unless otherwise noted, each effect lasts until the train leaves the plane. Some effects apply only to creatures outside the train.
The train enters a new plane whenever you like. Roll or choose from the options on the table to determine which plane the train is on and its accompanying effect. Once a train leaves a plane, it doesn't return to that plane for the rest of the adventure.
Planar Effects
| d6 | Plane and Effect |
|---|---|
| 1 | Acheron. The train flies over a vast battlefield where legions of devils clash with hordes of demons. Whenever one creature aboard the train deals damage to another creature aboard the train, both take 4 (1d8) psychic damage. |
| 2 | Elysium. All creatures aboard the train feel a sense of inner peace. No creature aboard the train can make an attack or cast a spell that deals damage. |
| 3 | Mount Celestia. Good-aligned creatures aboard the train gain a benefit of a bless spell that lasts until the train leaves Mount Celestia. |
| 4 | The Nine Hells. On one of the blisteringly cold layers of the Nine Hells (either Cania or Stygia), the train passes through a frigid gorge filled with whirlwinds of ice needles. Any creature outside the train takes 5 (2d4) cold damage plus 5 (2d4) piercing damage at the start of each of its turns. Modrons that normally patrol the outside of the train lock themselves in compartments for safety until the train leaves the plane. |
| 5 | Pandemonium. Howling darkness surrounds the train. Creatures outside the train are deafened. Outside the train, bright light becomes dim light, and dim light becomes darkness. |
| 6 | Ysgard. Silent, spectral warriors from Valhalla fly around the train on ghostly chariots pulled by ghostly steeds. Any creature aboard the train that would be reduced to 0 hit points drops to 1 hit point instead. |
Train Cars
The various train cars are shown on map 11.2. The earlier "x" section explains how to choose and arrange the cars.
E1: Caboose
The characters are assumed to be in this car when the train gets underway. As the train begins to pick up speed and lifts into the air, a disembodied voice says, "Next stop: Mechanus!" in Common, Modron, Celestial, Infernal, Abyssal, and Primordial.
Modrons in the Caboose
The duodrone attendant who punched the characters' tickets has another function aboard the train: making minor repairs while the train is in motion. As the train gets underway, the duodrone dons gear from a nearby locker (see "Locker" below). It then departs to perform its duties, whistling as it marches to the next car.
Hidden in the walls of the Caboose are four tridrones that emerge from their compartments to attack passengers who refuse to get their tickets punched or who perform an unlawful act, such as threatening the duodrone or plundering the locker.
Locker
The locker contains a blue engineer's hat and a crew uniform consisting of a tool belt and a pair of grimy overalls labeled with a number.
Rear Platform
A railing on the car's rearmost platform prevents creatures from stumbling over the edge and into the dizzying blur of mechanical arms that retrieve the trailing railway tracks. A bronze ladder welded to the car provides access to its roof.
E2: Abacus Car
The eleven modrons stationed here act as a mathematical calculator for passengers.
The self-proclaimed Math Wizard is a friendly duodrone. The Math Wizard speaks both Common and Modron.
The ten monodrones speak Modron only and are indifferent toward passengers. Each one holds a stack of ten placards numbered 0 through 9. When a creature inside the Abacus Car asks a mathematical question to which the answer is a number, the Math Wizard taps the podium with its wand and says, "Calculate!" In response, the monodrones select from their placards, shuffle around, and hold up their numerals to display the answer. The Math Wizard cheers "Huzzah!" after every successful calculation.
The monodrones do their best to calculate accurately, but sometimes they must estimate. Furthermore, if the ten monodrones are asked a question to which the answer exceeds 9,999,999,999 or the solution is uncountable, they scramble in circles while screaming in existential terror for a few moments before calmly returning to their positions.
Chalkboard
The chalkboard is covered with equations explaining, rather incomprehensibly, why the Great Modron March happens only once every 289 years. To anyone other than a modron, most of the equations are utter nonsense.
A character who studies the equations for at least 10 minutes can make a DC 25 Intelligence (Arcana) check at the end of that time. If the check fails, the character takes 3 (1d6) psychic damage and suffers a mild headache for the next hour. If the check succeeds, the character discovers a profound equation nestled among the others. Like a key, this equation unlocks something in the character's brain, with the effect determined by rolling on the Mysterious Equation table. A character who experiences this revelation gains no further benefit from studying the chalkboard equations. If any of the equations are erased, the modrons in the car turn hostile and attack, and no one can benefit from studying the equations.
Mysterious Equation
| d8 | Effect |
|---|---|
| 1–3 | You gain inspiration. |
| 4–5 | You gain proficiency in one tool of your choice. |
| 6 | You gain proficiency in one of the following skills of your choice: Deception, History, Insight, Investigation, Medicine, or Performance. |
| 7 | You learn a new language of your choice. |
| 8 | Your Intelligence score permanently increases by 2 (to a maximum of 20). |
E3: Aquarium Car
This car is completely flooded, and magic keeps the water from being displaced when either door is opened. Creatures that can't breathe underwater must hold their breath in the aquarium. Magic instantly dries creatures as they exit the water.
The aquarium can be slowly drained by removing a fist-sized plug near the base of the car's port-side wall. As an action, a character within reach of the plug can try to pull it out, doing so with a successful DC 17 Strength check. Once the plug is removed, the aquarium's water level decreases at a rate of 1 foot per minute. It takes 15 minutes for all the water to drain from the car. The car's fish can't survive more than a few minutes without water.
Angelic Statue
The alabaster statue is a petrified deva with a decanter of endless water. If any harm befalls the fish in the aquarium, the deva immediately reverts to flesh and chastises whoever is responsible. If the aquarium's plug was removed, the deva replaces it. If any water was drained from the car, the deva uses the decanter to replenish it. If any fish died, the deva uses raise dead spells to revive one fish per day for ten days. Once all is set right, the deva flies from the train and casts plane shift to return to Mount Celestia, taking the decanter with it.
E4: Cargo Car
The war machine comes from the wastelands of Avernus, the first layer of the Nine Hells. The vehicle isn't operational, but its hose-like sprayer is. A creature standing within 5 feet of the nozzle can take an action to cause the weapon to spray acidic bile in a 30-foot cone. Each creature in the cone must make a DC 12 Dexterity saving throw, taking 40 (9d8) acid damage on a failed save, or half as much on a successful one. A creature reduced to 0 hit points by this damage is dissolved, leaving behind any objects it was carrying or wearing. Once used, the sprayer can't be used again.
A creature that interacts with the war machine spooks six invisible imps lurking in its bent chassis. The imps fly out and attack the source of their fright while yelling, "I can't go back to jail!" in Infernal. If the infernal war machine's acid sprayer hasn't already been used, one of the imps uses it.
A character who sits in the driver's seat notices a glowing potion of resistance (fire) jammed in a dirty glove compartment along with six unpaid infernal parking tickets.
E5: Planartarium Car
The sixteen glowing sigils on the floor represent each of the Outer Planes, while the raised dais in the center of the room bears symbols of the four elemental Inner Planes. The wheel-shaped model above the dais represents the Outlands and its sixteen gate-towns. The tiny ring at the top of the spire represents Sigil.
A magical mote of golden light denotes the train's location. Since the train's travels are usually limited to the Inner Planes, the Outer Planes, and the Outlands, this mote can be seen floating above one of the symbols or above the model wheel representing the Outlands. If the train is in some other location not represented in this car, no mote is visible.
Donation Tube
The short tube rising from the floor near the dais has a slot large enough to insert coins, gemstones, and other small valuables. Such valuables are then teleported to the cart in x.
Whenever a creature drops at least 10 gp worth of treasure into the tube, Cosmo, the illusory modron, reappears. It thanks the donor and asks which plane of existence they'd like to learn about.
Cosmo can give a brief lecture on any plane of existence described in the Dungeon Master's Guide. If a character asks about a plane on the train's route, Cosmo also alludes to noteworthy planar effects. For example, if asked about the Nine Hells, the spectral duodrone might say, "Rest assured, the Concordant Express is reinforced to withstand extreme heat and extreme cold." Cosmo lectures about one plane per donation and vanishes after each lecture.
If a character inserts something worthless into the donation slot or otherwise tries to fool it with counterfeits and the like, the tube disgorges poisonous gas that quickly fills the compartment. This gas duplicates the effect of a stinking cloud spell that lasts for 1 minute or until it is dispersed.
E6: Passenger Car
This car contains three cozy passenger cabins and two privies (one at each end of the car). Quintus Malvesh, an aasimar cartographer, lies dead in the aisle (in the square marked X on x), and a detective is already on the case.
Illithid Detective
The detective is a lawful neutral mind flayer named Ignatius Inkblot. Seeing the characters, Ignatius lights a pipe with a match it holds with one of its face tentacles. The pipe exudes a green vapor that smells of absinthe. Since the characters weren't on the car when the murder occurred, Ignatius doesn't regard them as suspects and is friendly toward them. Ignatius can speak Common but loathes doing so; the mind flayer prefers to converse telepathically. Its tone is strident, and it uses stereotypical detective phrases such as "The game is afoot!" and "The devil is in the details!"
Ignatius tries to enlist the characters in its investigation. If they agree to help, the mind flayer asks them to look for clues and question suspects. (In the meantime, the mind flayer quietly casts detect thoughts, focusing on every creature in the Passenger Car.) Ignatius asks that no one leave the car until the mystery is solved. If the characters leave anyway, Ignatius solves the case without their help.
What Ignatius Knows
Ignatius has already determined that Quintus was killed while walking to his cabin from one of the Passenger Car's two privies. The aasimar's body lies outside the door to the middle cabin, which Quintus and another passenger shared. Ignatius was using the other privy at the time of Quintus's death and heard the aasimar gasp before hitting the floor. Ignatius quickly reached the scene, but the killer was nowhere in sight.
[image: Ignatius Inkblot, the great mind flayer detective, examines a corpse aboard the Concordant Express]
Murder Suspects
The suspects aboard the Passenger Car are as follows:
Abernathy Vernus (lawful evil cambion) is a friendly, ingratiating fellow who claims to have won a free tour aboard the Concordant Express. He insists that others call him Vern. No other passengers occupy his cabin (the one marked "a" on x), which Vern shares with a monodrone valet that answers to the name Higglesworth.
Ethlynn Stalaczic (neutral, drow mage) is a friendly, somewhat gullible dragonologist on a planar quest to find a "time dragon" (which may or may not be a real thing). Until a few moments ago, Ethlynn and Quintus were cabin mates. Ethlynn currently shares her cabin (the one marked "b" on x) with a monodrone valet called Bot.
Meldar (lawful neutral azer) is indifferent toward others, speaks nothing but Ignan, and provides curt answers to questions put to them. The azer is returning to the City of Brass after attending a smiths' convention in Bytopia. Meldar shares a cabin (the one marked "c" on x) with Ignatius Inkblot and a monodrone valet known as Orb.
The monodrones never leave the train. Ignatius was already aboard when Meldar boarded the train a day ago in Bytopia. The other suspects boarded the train near Excelsior (a gate-town in the Outlands) shortly before the characters came aboard.
Murder Victim
Characters can examine Quintus or cast spells on the corpse. The following information can be learned by doing so:
- Examining the Corpse. A character who examines Quintus and succeeds on a DC 11 Intelligence (Arcana) or Wisdom (Medicine) check determines that the aasimar was killed by three bolts of magical force identical to those created by a magic missile spell. Given where the body fell, the direction Quintus was walking when he died, and where the wounds on the body are located, a character can deduce, with a successful DC 16 Intelligence (Investigation) check, that the killer likely didn't come from Meldar's cabin.
- Raising the Dead. A character who has the raise dead spell prepared can use it to restore Quintus to life. (The devas in xand x can also provide this service, if asked nicely.) Quintus is chaotic neutral and uses the noble stat block, although he is unarmored and carries no weapons. Alive, the aasimar is less cooperative than when he was dead, for reasons explained in the "x" section below. He offers no possible reasons for why someone would want to kill him.
- Speaking with the Dead. If a speak with dead spell is cast on the corpse, the aasimar's spirit answers questions honestly. Quintus did not see his killer, but he knows one reason why every other passenger in this car (besides Ignatius) might want him dead. These reasons are summarized in the x.
Searching the Cabins
Characters can search for clues in the passenger cabins and question the modron valet in each one:
- Cabin A. This cabin holds Vern's battered suitcase, which contains two traveler's outfits, three odd-looking compasses, and a set of tinker's tools. If asked about the compasses, Vern says he builds and repairs them to pass the time on long trips.
- Cabin B. Ethlynn shared this cabin with the murder victim and knows Quintus was a cartographer. Ethlynn confirms that Quintus left their cabin to use the privy at one end of the train car. Characters who search the cabin find Quintus's satchel, which contains two spare traveler's outfits, a set of cartographer's tools, and a map case containing what look like ancient treasure maps. A similar map, stolen by Ethlynn while Quintus was visiting the privy, is stuffed in her spider silk handbag. (Ethlynn insists Quintus gave the map to her, which he never did. He did, however, tell her that the map shows the way to a time dragon's lair, which it does not.) A character who spends 1 minute examining any one of Quintus's maps can, with a successful DC 16 Intelligence (Investigation) check, cast serious doubt on the map's accuracy.
- Cabin C. Meldar and Ignatius share this cabin, which contains nothing incriminating. Its occupants travel light.
- Questioning the Modrons. Monodrone valets aboard the Concordant Express have built-in language interpreters instead of voice boxes; consequently, they can understand any spoken language but can't speak. Bot and Orb shrug their shoulders if questioned about the murder (of which they know nothing). Higglesworth simply points to itself if questioned about the murder.
Solving the Mystery
The monodrone Higglesworth killed Quintus using a wand of magic missiles, which is hidden in a secret compartment inside the monodrone's spherical body. The monodrone won't subject itself to inspection and attacks anyone who tries to search or dismantle it. Its impeccable valet programming prevents it from incriminating passengers or accusing them of any wrongdoing.
Higglesworth did not commit the crime willingly. The cambion Vern used his tinker's tools and magical know-how to reprogram the monodrone valet to murder Quintus using a wand Vern pilfered from a wizard's apprentice in Excelsior. Vern then used the modron's body to hide the murder weapon and instructed Higglesworth not to tolerate invasive scrutiny.
Murder Weapon
A character can use an action to search Higglesworth for a secret compartment, finding it with a successful DC 13 Wisdom (Perception) check, but this can be done only while the monodrone is incapacitated. The same is true for opening the compartment, which requires another action, thieves' tools or tinker's tools, and a successful DC 11 Dexterity check. Opening the compartment causes the wand to tumble out.
If Higglesworth is reduced to 0 hit points, its body disintegrates, but the wand of magic missiles hidden inside it remains.
One of the wand's charges has been expended—the same charge that killed Quintus.
Motive
Vern is a con artist who makes and sells "magic compasses" to gullible folk looking for an easy way to find that which their hearts desire. Quintus, also a con artist, made and sold bogus treasure maps. Vern and Quintus both identified Ethlynn as a likely mark, but Quintus got to her first by preying on her dream of finding a time dragon's lair. Vern decided to eliminate the competition while laying the blame on a malfunctioning modron that can't speak in its own defense.
J'Accuse
If the characters accuse Ethlynn or Meldar of murdering Quintus, Ignatius telepathically warns the characters that their investigation has gone "off the rails." He then recommends they "look for clues within clues" and "try to understand the motive behind the killing." Gifted with the ability to cast detect thoughts at will, Ignatius has already identified Vern as the individual responsible for Quintus's death, but Ignatius wants the characters to see the truth for themselves—not simply take a mind flayer's word for it.
Case Closed
The mystery concludes with Ignatius confining Vern to his cabin until the authorities in Mechanus remove the cambion from the train. If the characters don't have the means to raise Quintus from the dead, Ignatius suggests they speak to the deva guarding the Jail Car and convince the angel to revive the dead aasimar. The characters are free to keep the wand of magic missiles, since Ignatius doesn't need it to make a case against Vern.
Ignatius won't press Ethlynn on the theft of Quintus's bogus map, but characters may do so. Ethlynn can be guilted into returning the map and apologizing for the theft. As for Quintus, the aasimar won't admit to any wrongdoing unless magic is used to coerce him.
Murder Suspects
| Suspect | Possible Motive |
|---|---|
| Abernathy Vernus | The cambion seemed upset, maybe even jealous, that Ethlynn and Quintus were getting along so well. The cambion seemed to have his heart set on spending more time with Ethlynn, which necessitated getting rid of Quintus. |
| Ethlynn Stalaczic | Ethlynn was eyeballing Quintus's maps. Killing Quintus would allow her to steal the maps without anyone knowing. |
| Meldar | Quintus referred to Meldar as a "hothead" when he didn't think the azer was close enough to hear him. Killing Quintus could've been payback for the insult. (Since Meldar knows only one language—Ignan—and the insult wasn't spoken in that tongue, this motive evaporates quickly.) |
E7: Temple Car
The priest is, in fact, a gray slaad using its Change Shape ability to fool the characters. The slaad was sent here to kill them, plain and simple. It killed the real priest, stole his robes, and threw his body and holy symbol off the train.
The slaad works for an evil, multiverse-spanning organization called the Syndicate of Terror, Extortion, Assassination, and Larceny (STEAL), which has been spying on the characters for some time and wants their mission aboard the Concordant Express to fail. (This is doubly true if the characters are working for STEAL's rival, the Golden Vault.) If you're weaving multiple adventures from this anthology into your campaign, one or more villains from earlier adventures might have secret ties to this evil organization. Likely candidates (assuming they're still alive) include Quentin Togglepocket from "The Stygian Gambit," Guildmaster Dusk from "Masterpiece Imbroglio," and Nixylanna Vidorant from "Vidorant's Vault." If you're using the rivals described in this book's x, their patron might be a STEAL operative.
One of STEAL's operatives, having recently acquired the gray slaad's control gem, used the gem to command the slaad to slip aboard the Concordant Express and kill the characters on sight. The slaad loathes being surrounded by modrons on the train and fights to the death.
Scrying Sensor
The slaad's master watches the battle unfold through an invisible scrying sensor like the one created by a scrying spell. If the characters defeat the slaad, a magically altered voice issues from the invisible sensor and says in Common, "So much for that. Next time you won't be so lucky!" If the characters are working for the Golden Vault, the voice adds, "The Golden Vault won't be able to protect you from our wrath." The scrying sensor then disappears.
E8: Jail Car
This soundproof car is two stories tall (30 feet high) and encased in thick iron. Four pentadrones guard the rooftop. These guards are positioned near the corners of the roof, allowing them to spot trouble coming from the sides of the car.
The outer doors of the car are locked tight, as is the 10-foot-square skylight in the roof. As an action, a character with thieves' tools can try to open one of the doors or the skylight, doing so with a successful DC 17 Dexterity check. The skylight can also be shattered; it is made of thick glass and has AC 13, 27 hit points, and immunity to poison and psychic damage. Conversely, the doors are too strong to be forced open by anything other than knock spells or similar magic.
When the characters enter the car, read or paraphrase the following:
Omid the Deva
The angel guarding the Jail Car is Omid, a deva with fiery instead of feathery wings. Omid has orders to deliver the Stranger safely to Mechanus, where judgment awaits.
The deva's glowing mace is reminiscent of a large key. The head of the mace lines up neatly with the gear-shaped keyhole on each of the car's eight cell doors. As an action, a character can use the mace-key to unlock any one of these doors, which can be opened no other way.
Omid remains in the Jail Car and can't be lured from it. When the deva encounters the characters, read the following:
The characters need not resort to violence to obtain the deva's mace-key. Here are some alternate approaches:
- Clever Deception. The characters can pose as emissaries of a jurisdiction with greater claim to the Stranger's custody. Convincing Omid to release the Stranger requires a successful DC 17 group Charisma (Deception) check. If the characters used a forgery kit to create documentation to support their claim, the group check is made with advantage.
- Convincing Argument. Since Omid knows little about the Stranger, a character can convince the deva that the outlaw has been wrongly accused and should be released. Making the argument might take a minute or two, after which the character must succeed on a DC 17 Charisma (Persuasion) check to secure the Stranger's release.
- Friendly Game. A character who has a gaming set can challenge the deva to a friendly game. Omid loves games and is too proud (and bored) not to accept. If the character wins the game, Omid allows the party to speak with the Stranger (but not set them free). Determine the game's outcome by having the deva's challenger make a DC 19 Intelligence check. Proficiency with the gaming set allows the character to add their proficiency bonus to their roll. If the check is successful, the character wins. On a failed check, the character can opt to cheat in the late stages of the game and make a DC 19 Charisma (Deception) check. A successful check overrides the earlier failure. If the character loses gracefully and didn't cheat, the deva (a gracious winner) still allows the party to speak with the Stranger.
Cells
[image: The Stranger]
The door to each cell opens into a 10-foot-square extradimensional space brightly lit by magic. The cells and their contents are as follows:
- Cell 1. This cell contains a hostile nycaloth known as Dardo (not its true name). If someone opens the door to its cell, Dardo tries to exit the cell on its next turn, attacking anyone who stands in its way. The nycaloth then tries to leave the train. The Stranger (see below) happens to know Dardo's true name: a simple math equation. The characters can use this knowledge to keep the nycaloth from attacking them, or to force it to work for them.
- Cell 2. This cell is empty.
- Cell 3. A bench against the far wall has a +2 rod of the pact keeper resting on it. The cell is otherwise empty.
- Cell 4. This cell contains a friendly erinyes who recently helped an efreeti named Vrakir get his hands on the Book of Vile Darkness. Speaking with this prisoner might kick off "Fire and Darkness," another adventure in this book. The Stranger (see below) doesn't know this erinyes's true name.
- Cell 5. This cell is empty.
- Cell 6. This cell is empty.
- Cell 7. A monodrone janitor accidentally locked itself in this cell.
- Cell 8. This cell contains the Stranger (see below).
The Stranger
This individual looks like a human with a flat-brimmed leather hat and a tattered traveler's cloak. The Stranger's face is permanently obscured behind a shifting blur like that of a deep desert haze. The Stranger is chaotic neutral and uses the archmage stat block, though they abhor combat. The Stranger wears an invisible ring of mind shielding that thwarts magical attempts to read their thoughts. The Stranger also wears dimensional shackles but is eager to be rid of them. One touch from Omid's mace-key causes the shackles to fall off, freeing the Stranger.
The Stranger is initially indifferent to the characters but becomes friendly if presented with the prospect of escape, at which point the Stranger replies in a gravelly voice:
The Stranger promises to recite the true names the characters seek in exchange for freedom but warns them of the heavy toll such knowledge carries.
If the characters are after the true names of Karnyros, Errtok, and Hexalanthe, the Stranger reveals the following once free of the dimensional shackles and outside the cell:
- Karnyros's true name is a series of guttural growls and grimaces, followed by a sound like a popping balloon.
- Errtok's true name is Ar-lothe Gothu Ka.
- Hexalanthe's true name is a low-toned, rhythmic chant accompanied by a series of hand gestures, dance moves, and drumrolls.
If the characters are after the true name of some other creature, perhaps a fiendish nemesis or tenuous planar ally, the Stranger might know that creature's true name as well and can reveal it to the characters. Even if the Stranger doesn't know a particular true name, they can give characters the true names of one or more Fiends who have the power to help the characters in some other way.
If you have trouble coming up with ideas for new true names, roll on the x at the end of this adventure when you need one.
E9: Engine Car
The sapient Engine Car is the source of the deep, booming voice. The car speaks Common and Modron. While it's moving and not talking, the Engine Car labors through an endless chain of short, forceful breaths timed with each rhythmic churn of its mechanisms. Its undercarriage chatters as dozens of mechanical arms lay railway tracks before the train.
Inside the car, two monodrones stoke the fire in the furnace by shoveling loot into it from a nearby cart (see "x" below). A shield guardian stands next to the cart, guarding the treasure from thieves. Thanks to its Spell Storing trait, the guardian can cast sleep (4th-level version) once.
[image: A monodrone shovels treasure into the locomotive's engine]
Furnace
Any object not being worn or carried that is placed inside the blazing furnace is incinerated instantly. Even magic items succumb to the blazing furnace, though the flames aren't powerful enough to harm artifacts.
If the furnace isn't replenished every hour with at least 100 gp worth of treasure, the Engine Car sputters and the train comes to a halt, causing a guard patrol (see "x" earlier in the adventure) to investigate.
A creature that enters the furnace for the first time on a turn or starts its turn there takes 55 (10d10) fire damage. A creature reduced to 0 hit points by this damage dies and is reduced to a pile of ash.
The furnace door can be latched from the outside. A creature trapped inside the furnace can use an action to try to force open the door, doing so with a successful DC 20 Strength (Athletics) check.
Treasure
The treasure cart contains 3,500 gp, 6,000 sp, and 1,200 cp. Scattered among the coins are the following items:
- Five amethysts (100 gp each)
- Gilded mind flayer skull (150 gp)
- Horn of Valhalla (silver)
- Suit of mithral armor (chainmail)
- Potion of healing (greater)
- Silvered +3 greatsword that once belonged to a githyanki knight
Conclusion
After imparting the true names, the freed Stranger tips their hat and leaps from the train. Once out of range of the train's teleportation ward, the Stranger casts plane shift and disappears. The characters can leave the Concordant Express in a similar fashion, or they can remain on the train until it arrives in Mechanus and secure safe passage home from there. Whether or not they helped solve the murder in the Passenger Car (x), characters who disembark in Mechanus see Ignatius Inkblot, the mind flayer detective, escorting the cambion Abernathy Vernus off the train and into the waiting arms of a group of modrons.
For the Golden Vault
If the characters are working for the Golden Vault, the organization sends the group's contact to retrieve the true names the day after the characters record them. This operative offers the characters a rare magic item of their choice (subject to your approval) as payment, which is delivered to the characters the next day.
Other Rewards
If the characters helped solve the murder mystery aboard the Concordant Express, the mind flayer detective Ignatius Inkblot uses its plane shift spell to deliver a wrapped parcel to the characters several days later. The parcel contains a token of the illithid's esteem: a masterfully crafted magnifying glass worth 1,000 gp.
Characters can also leverage any true names they learn into further rewards, as discussed below:
- Home Ownership. Knowing a creature's true name may entitle the characters to that creature's property, such as a parcel of land, lair, or stronghold.
- Slayer's Weapon. A master smith might be able to work the true name of a creature into an arrow of slaying or other target-specific magic item.
Further Adventures
The characters might have made a number of planar enemies during this heist. Subsequent adventures could include the following:
STEAL. The rival organization STEAL (see x) might figure prominently in future adventures. At higher levels, run-ins with STEAL operatives or raids on STEAL vaults might place the characters in conflict with the syndicate's leaders, including arcanaloths and ultroloths with true names only the Stranger knows.
- Trials and Tribulations. The characters might be forced to stand before a tribunal in Mechanus for aiding an interplanar fugitive or answer to a powerful Celestial for slaying an angel.
- True Name Terror. Characters who learn the true names of powerful Fiends are marked for death by those Fiends, which send powerful underlings to slay the characters.
Random True Names
| d100 | True Name |
|---|---|
| 01–03 | Sequence of musical notes played on a lyre |
| 04–05 | "Zow Chokk Garthagua" |
| 06–07 | "Lureff Zadil" |
| 08–09 | Sound of a bucket dropped on the floor |
| 10–11 | "Batridd Morath" |
| 12–13 | "Agh Gizzirah Korondis" |
| 14–15 | Third line of an obscure Auran lullaby |
| 16–17 | "Naelurec" ("cerulean" backward) |
| 18–19 | "Si Uulth Uurek" |
| 20–21 | Sound of four eggs sizzling in a frying pan |
| 22–23 | "Lamoura" |
| 24–25 | "Haraknar Orvorag" |
| 26–27 | Nine-second hum of a tuning fork |
| 28–29 | "Kyrvaash Cesvyr" |
| 30–31 | "Tsul Vandar" |
| 32–33 | Sound of three pages tearing from a book |
| 34–35 | "Vrah Koruun" |
| 36–37 | "Jal-Shoth" |
| 38–39 | Seven tolls of an iron bell |
| 40–41 | "Barak-Shivad of the Night Realm" |
| 42–43 | "Winterglory" |
| 44–45 | Short whistle, followed by two long ones |
| 46–47 | "Kelefis the Thrice-Hated" |
| 48–49 | "Nefarion" |
| 50–52 | Three specific prime numbers strung together |
| 53–54 | "Zizz-Ganneth" |
| 55–56 | "Red Rust" |
| 57–59 | Sequence of red and blue lights flashing |
| 60–61 | "Xurgranach" |
| 62–63 | "Enchridus 3291" |
| 64–65 | Last spoken words of a long-dead hero |
| 66–67 | "Valmorag the White" |
| 68–69 | "Suzakiro Arzuun of the Rusty Blades" |
| 70–71 | Sound of fingers drumming on a table |
| 72–73 | "Myranna Vos Aeldar" |
| 74–75 | "Kzokzys" |
| 76–77 | Gasp of someone stabbed through the heart |
| 78–79 | "U'chud, the Eye of Zefir-Zaskos" |
| 80–81 | "Quas Quannok" |
| 82–83 | Sad mewling of a kitten |
| 84–85 | "Skuzrayle" |
| 86–87 | "Nebek Velflam Von Qwizzid" |
| 88–89 | Sound of a lute being smashed to pieces |
| 90–91 | "Old Sinisyphere" |
| 92–93 | "Ghax'ru the Abominable" |
| 94–96 | Sound of three acorns crunched between teeth |
| 97–98 | "Knob" |
| 99–00 | "The Nameless One" |