Alpha Labs - Sector 3: Union Aerospace Science Division is the seventh level of Doom 3. It contains a very hidden plasma gun and an optional chaingun. All the locker codes are the same, due to the incompetence of the employees.
For cells of the form x/y/z, x corresponds to Recruit difficulty, y to Marine, and z to Veteran/Nightmare.
Items that can only be acquired by using console commands are excluded.
Storage Cabinet #047: Ammunition - 123
Storage Cabinet #048: Ammunition - 123
Storage Cabinet #049: Ammunition - 123
To get the hidden Plasma Gun, the player needs to open "Ventilation Access Grate 3" through a touch-screen, located in a L-shaped console, on the right just after accessing a standard door (before the room with a lift). After opening the access grate, the player must come back through the door he just entered and immediately turn left; he should see some boxes and the ventilation access opened. First item in the ventilation duct is a medkit, then following the little conduit, the player must turn right, watching a room through a grate: shoot it (one shotgun shell should do the job) and the Plasma Gun is just ahead, on the pipes; then he can follow the pipes-road on the left to find other useful stuff, like armor shards.