Second Sight Easter Egg - Second Sight - Dirty Laundry

In level "Entrapped", in the room with one lever in the middle of it (which you pull and guards come out and start shooting at you) there is a crack in the brick wall directly opposite the exit door.

Slip through it using 'E' and follow the narrow passage through the wall. You will get to a short corridoor in dis-repair, with greenish walls and tiles coming out of the floor. At the end of this corridoor is a laundry room with several broken looking washing machines, a pile of dirty linen and soap lying about!