The Warlock's Crypt
"The Warlock's Crypt" is a fext and noctiny lair suitable for four 9th-level characters. This adventure can be completed in a single session.
An ancient warlock king known as the King in Silver, whose patron was Death itself, knew he was growing old and would soon die. The aging king pledged the souls of his two sons, the Black Prince and the Red Prince, to Death in exchange for his own eternal life. As the final worlds of the pledge pass his lips, the old king collapsed to the ground, dead. Elsewhere in the castle, the two young princes died suddenly in their sleep. All three were interred in the royal crypt within a nearby burial mound. ultimately, the king got what he asked for - he and his suns were returned to life as fext in the service of Death itself.
When the fext awoke and climbed out of their coffins, they were confused because it seemed they were trapped within the small royal crypt. Then, the King in Silver discovered a secret door leading to a hidden stone stair that descended into a complex of ancient tunnels and chambers. At the far end of the complex, the fext discovered a second set of ancient stone stairs leading up through a shaft to a hidden exit on the surface.
The three fext now lurk within the lower chambers, doing their patron's dark bidding. When commanded, they creep forth from the crypt to spread death during the dark of night.