Nothing, it is empty.

Sonja stands in a simple ten by ten foot square room carved from simple sandstone. A single oil lantern hanging from the ceiling gives light. The she-bandit, however, frowns at the strange drawing painted around the hole. It is of a tentacle monster with various runes and apparently magic scripts written alongside the picture. The only exit is a single hallway which travels about thirty feet and ends in wall. Moving down the hallway Sonja silently mutters curses to herself. Her drenched boots make a faint squishing sound and she is leaving behind wet footprints, but this cannot be helped.

Though the passageway ends abruptly, it is clear from the mechanisms that frame the wall and the attached lever, this is the backside of a secret panel. "So the garbage disposal is also a secret exit." Sonja reasons as she listens carefully to the panel. Hearing nothing the she-bandit flips the lever and the panel slides open onto a perpendicular running hallway. Within a few seconds the door closes by itself, forcing Sonja to jump into the new passage. Looking back she can hardly make out the secret door and there seems to be no switch on this side. Across from the door is a mounted torch, and upon further inspection, the mounting fixture is a lever onto itself. The passage away goes to the right and the left. Either direction travels about fifth feet and ends in a heavy wood door.