Inside a small secret compartment is a box. In the box is a Ring of One Wish. You may not use the wish in this dungeon except to restore a comrade to life, and even so, he will come back with all his attributes halved. [Outside the dungeon your character may use the wish for whatever the Game Master will let you get away with.]
There is nothing else to do here. You may now return to either the fork or the intersection.