Phase 2: We started in B-4829 and had nowhere to go but up since our other options were locked.
Phase 3: We found ourselves in C-6517 with an unpowered orange shuttle and some papers. We went south.
Phase 4: I got poisoned by radiation in C-5142, but I'm better now. We went south.
Phase 5: We found a syringe that said "pain transfer" which as far as we have seen, does nothing if injected. Aldo was shot, we selfishly decided not to revive him (though I use "we" very loosely) and then headed down the elevator to here.
Phase 5 was C-3904.

Like this:

Group 1 goes west
Group 2 goes east
Group 3 goes south
Group 4 stays here with Francis.

Phase 7:

Groups 1-3 return here.
Group 4 is forced to move, so they go down the elevator.

Phase 8:

Groups 1-3 go down the elevator.
Group 4 waits for groups 1-3 to catch up.