Hall with locked doors

[Guest7]

HI, I'm back again, enjoying Black Plague. And as usual, I'm stuck on something probably easy.
In the hall way with locked doors (after the laser beams and dead guy on the floor) and you need keys to the rooms, and a key or something to open the electrical box? (or not?). Anyways, how do I get out of this hall way, as the new Out door, won't budge. I've missed a step or two or something and don't know what.
Thanks!