Subject Doors

There are no more doors in this room, but back in the main room there are 4 more doors besides the one in the center of the north wall with the lock on it.

In the main room there are 13 doors total. 1 is the door you came in. 1 is the door with the lock. That leaves 11 other doors, 7 of which you have opened. 4 more to go.