5. The Bone Room
As the players near the room the stonework in the hall becomes paved with bones. The open room's floor, ceiling and walls are made of bone. Jagged, broken off bones jut out in every direction making travel through here dangerous. The ceiling dips and the floor swells making some areas in the room narrow enough in height that only a halfling could pass without stooping.
Hidden among the bones are two bone demons (or Babaus, pg.213 OSRIC). It is virtually impossible to distinguish the demons among the bones. The demons have rigged a trap for the players, as they walk towards the corridor in the east wall a section of the bone ceiling will collapse on one or more of them (4d6 damage and for every 6 rolled a limb is pinned). The demons will attack after the trap is sprung.
The demons do not want to kill the players, but to subdue them. Baiyatus (see room 6.) needs more souls to carve a permanent gate for his demons to enter into this world. The secret door in the eastern wall is concealled behind a movable bone door that blends in with the surroundings.
Any treasure has been given to Baiyatus, but among bones and only a Detect Magic spell would be able to find it is a wand made of bone. It is a Wand of Reincarnate with 2 charges.