(OOC: Siohban did not in fact go with you. You can actually see her looking around where you were, trying to figure out where you went. The small chits that each of you had are likewise no longer here.)
The prying eyes reveal an empty room, as does the exploration. The far wall, however, is different. While the black stone the room is made of is more of a very dark gray stone blocks, the back wall is solid stone of the deepest black imaginable, it seems to devour light.
Again without knowing how they know, there is an absolute certainty, touching the wall will start the trial.