OOC: I'm assuming "long corridor" refers to the hall of moving murals. There's another long corridor (in the first set of rotations posted earlier), the one lined with tiger heads, but that appears to be a dead end. [Map 1]
The first arrangement of the hall of moving murals leads to the room where the sleep symbol was activated. A door from here, once checked and deemed safe by Mhairi, leads to another room, simple and empty. There is a way off from it, but it is blocked by a wall - perhaps in another arrangement of this moving dungeon this leads to elsewhere.
The second arrangement of the hall of moving murals leads to a new room, decorated in a delicate mosaic of wasps. Swarms and swarms of wasps cunningly worked into a tessalating pattern. There are two doors leading off from this room. [Map 2]