Human: Write a detailed description of a spooky cavern with a ceiling, scabrous crust, and ichor. Assistant: 
A thick black ichor creeps down the southern wall of the chamber from a thin crack where the smooth wall slab meets the rough rock of the ceiling. The excretion has built up at the base of the wall and solidified into a scabrous crust. Remarkably, the room is free of the ubiquitous dust and rubble encountered elsewhere.