Setting	00 Agent
Target	1:20
Cheat	Invisibility
Achieved	1:19

This is one of the most difficult cheats to achieve, right up there with Facility. However, with Facility you can complete the level with plenty of time to spare, it just takes time. With Archive, I have only managed to complete the level in 1:19, only beating the target by one second.

Hints: Avoid shooting whenever possible on this level, it only attracts guards. Run sideways and practice your route until you can get through without getting held up on obstacles.

You start in a room with two guards. Run as quickly as you can to the guard opposite you, avoiding the weapons. Give the guard a chop and you should get a DD7 and the key to the room. Get out of the room and head right down the corridor, avoiding the guard standing here. Don't waste time shooting at anyone. Head straight up the stairs and double back down the corridor in the opposite direction you came, arming yourself with the DD7 as you go. You'll come to a crossroad junction, head right. There will be a guard here, don't shoot at him but go straight past him, dodging the crates and through the door. On the other side of the door you're on a balcony overlooking a big room. Head straight through the double doors immediately on your left. Once in this room you want to move across the room to your right, and head for the single door on the far side of the room where Natalya is. Open the door and let Natalya see you. Then, turn around and go directly in the opposite direction. You should see a double door directly opposite you with a guard in front of it.

Ignore the guard, if you shoot here, you'll end up with guards the other side of the door. Head through these double doors, there are stairs directly in front of you. Go down these into the big room. Stick to the right wall and go on, there's a door half way down the wall. Open this, go through and head left, sticking to the wall. Ahead of you there's another door in the corner of the room. Go through this and then through the door directly to your left. Now you're in the room with Mishkin, he'll be standing in front of the safe. Go straight to him and he'll start talking.

Now the next stage is tricky, if guards come into the room at this point you're going to have trouble finishing the level. This is what I have found works in stopping the guards coming in.
As soon as Mishkin starts talking, double back and close the door into this room. Back off from the door and wait a bit - don't worry, you keep talking to Mishkin while you're doing this. After a few moments, Natalya should open the door and come in. Sprint forwards and close the door, then turn left and run around the crates so you're standing behind Mishkin, in front of the safe. Avoid Natalya, if she starts talking to you she'll slow down Mishkin's speech.

Wait in front of the safe until Mishkin gives you the key. Immediately open the safe, back off to let it open then grab the flight recorder. Turn around and run in the opposite direction to the door - this should be other door to the room, the one you didn't come through in to the room. Open it, head left and turn round the corner. Head straight forwards and go through the door at the end of this corridor. You're now in the room with the windows you escape from. As you enter this room, angle right and head for the window, shooting it out as you run into it. Don't wait for Natalya, bolt straight through it.
With luck you should manage to get out in under 1:20.

This level takes a lot of practice, you'll need to keep shaving off seconds by running sideways and perfecting your route, but you should get there. If you've managed this level in under 1:19, let me know.