Mission 1: Arkangelsk
Part II: Facility

Extra:
On Secret or 00 Agent mode, if you shoot a scientist in the hand and then in the foot, they'll pull a DD44 on you! After a while, they'll eventually chuck a grenade at you! By the way, they have pretty nice shots for scientists.

At the start, you are in the air vent. Move forward, and to the left. Follow the tunnel until you see an opening. You can shoot a guard's head from here with your PP7. Go through the opening, and open the door. Around the corner to the right there is a guard. Quietly kill him, and in the door in front of you and the door to the left of that there should be two guards. Kill them if you want to. Collect their ammo, and head out the main door. Go through the next door, and stop at the steps. Here you can either run down and massacre all the guards or make a really loud noise with the KF7, and shoot them at the bottom of the stairs as they pile up to get shot. Someone should also come out from the door around the corner from the top of the stairs. Watch out for him. Now, that's finished, go down, swing around past the boxes through the small door. Shoot the guard who has Keycard B. Go back near the stairs, and go through the metal door. Go to the computer which activates the remote door, and press B. Go out, go down the corridor to the left (where there is some body armour on one of the boxes), turn left, open the door, and go through the next open door. To your left there are some lockers and two guards. Kill them if you like (it makes it easier). Open the next metal door, and quickly shoot the three guards in the distance, as they have rather good shots. Now, QUICKLY go through and hide behind one of the pillars. A handful of guards should come from the door you came through. Kill them.

The next thing to do is to check both rooms on the left and right for the double-agent scientist Dr Doak. He'll have the door decoder for the bottling room which you'll need later. If he's not here, he should be in the next area. Go through the door far ahead, and through the next one. A guard should come walking by, and start shooting. As soon as you kill him, more will appear from the hallway and some from the room ahead. Kill them all. Go into the room ahead of you, and kill any remaining guards. On Agent and Secret Agent there should be body armour at the end of the room. Facing the door, there are two computer panels. If you haven't found Dr Doak yet, activate the computer on your left. Otherwise, activate the one on your right. If you haven't found him, go out, and follow the corridor on the left, and through the door. Activate the next door, and go up the steps. He should be around on the floor if he's here, and there are two lots of guards posted on two of the smaller higher areas. Oh, and by the way, don't shoot any barrels (and preferably computers) here, as it will create a gas leak, and you will be trapped, as the remote door will be locked. You will die.

Exit out, go back to the computer room and activate the other computer. Go down the right corridor, and through the open door. There are some guards behind the boxes, and more guards will come if you shoot them. Ascend the stairs, and after turning 2 corners, there will be a guard in the distance. Take him out, and more will follow. Go down the hallway near the intersection, and behind the pillar there are 2 guards. Even more will appear from the other hallway. There are three glass encased rooms, and if you haven't found Dr Doak yet, he will be around here. He will go up to you if you're close enough, and give you the decoder. Oh, and if you shoot the scientists on Secret or 00 Agent mode in the hand and the leg, they'll pull a Dostovei on you. And they have pretty nice shots for scientists!

Go down the last hallway to a large metal door. On Agent, just press B, but on Secret Agent and 00 Agent you must select the decoder from your inventory list, and press Z to enact it. After a few seconds it will open. Along the walkway to the left and inside the room are a few more guards, but they're not all that important. Go down the stairs where your fellow agent 006, Trevelyan will start talking to you. Now, switch to your remote mines, and plant one on each of the back tanks. When that's done, make sure both of you are clear from them, and press Z to detonate them (while you're on the watch detonator). Just exit through the door or the conveyor belt to complete the level, but if you stick around, LOTS AND LOTS of guards will come, with VERY good aim. An officer, Ourumov, will hold Trevelyan prisoner, and shoot him in the head. It's not wise to stick around.