The walls of this room are covered with paintings depicting pairs of standing minotaurs, approximately nine feet high, facing each other. One of the minotaurs is painted over a locked door, with a keyhole in its torso. The minotaur directly across from it has a small key, about two inches long, painted on its torso roughly in the location of the heart. Standing motionless in the center of the room is the shadowy form of an actual, insubstantial minotaur. A shadowy key floats inside the minotaur right where its heart would be.
Touching the insubstantial minotaur will cause it to solidify as a stone statue and attack. Touching the painted minotaur with the key will have the same effect. The first touch will activate it for one round, the second for two, and every touch thereafter for three rounds of combat. Weapons cannot damage it, but can be used to turn it aside to prevent damage to others. It will attack with blind fury and is incapable of speech, but it cannot pass the doors of the room. If all persons leave the room at any time, the room will "reset" to its original configuration.
At the end of its turn on the last round of activation, the stone minotaur will freeze in whatever position it was in and return to insubstantiality. The painted minotaur with the key will also change its stance and position to match that of the shadow-minotaur.
Solution 1: Touching just the painted key will cause the insubstantial key to solidify and drop to the floor. However, PCs must be careful to take the solid key without touching the shadow-minotaur's feet!
Solution 2: If the painted minotaur with the key is maneuvered around the room so that it crosses the painted minotaur with the lock, the door will unlock.
Solution 3: The stone minotaur can be maneuvered to crash into the door and break it down.
Solution 4: Use the shadow of a hand to take the shadow-key out of the insubstantial minotaur without activating the statue. The shadow-key must then be solidified by touching it with something substantial, or by touching the painted key.