the chamber is an elaborate, hypertech hospital, constructed for the maintenance of three beings -- the precogs. they are triplets -- two of the precogs are male, one is female.
in an image just like the scene in the beginning of the movie, the three faces of the precogs hover in the misty darkness. their closed eyes open in sudden unison. they speak as one.
four officers stand guard in the chamber. they listen to the orders coming in on their earpieces. three of the guards rush out of the room, one stays behind.
in the chamber are one guard, two technicians, and three precogs. and all of them are left in sudden darkness, as the power is cut.
the room is utterly dark and silent. the silence is broken by the sound of something rolling across the floor. somebody speaks, probably the guard.