If the party is defeated, stabilized characters awaken after 1d4 hours to find themselves cocooned in sticky webs and suspended 10 feet off the floor, with spider eggs implanted in their bodies. A cocooned character is restrained and can use its action to try to escape by making a successful DC 15 Strength check.
Spider eggs implanted in a host hatch in 2d12 hours, killing the host as the baby spiders chew their way out. This infestation functions like a disease. A lesser restoration spell or similar magic cast upon the host kills the spider eggs, ending the threat.