Ah, the famous "Invincibility Cheat." Yes it is possible because I, a non-professional Goldeneyer, got it! Anyway, try and understand this. Skip the cinemas (always skip cinemas) and side step thru the vents. As you are dropping down into the stall, switch to remote mines. Head out the bathroom doors and proceed down the stairs. If your timing is right, there should be a guard who just walked past the foot of the staircase. Throw one mine on the two stacked crates nearest you, turn to the left and go thru the door directly behind you and next to the staircase. While running towards the door, detonate the mine using the A & B technique. After detonating, you should have killed the guard I mentioned, plus the 3 in the romm w/the computer. Go thru the door and kill the guard with the Clearence B card. Use the pp7 and do it quickly because once you fire it, the guys in the bathroom will come down. Turn back around and go thru the door you just came through and if everything is as it should be, a guard in the room w/the computer has conviently opened the door for you and has conviently died. Hurry in and activate the Security door. Sometimes you'll be too slow and the guys from the bathroom will have shot the computer and it'll kill you. After activating, side step your way past the firing guards towards the first metal door that requires the Clearence B card. open it and move through the second door (which is already open...) and switch to your soviet, which, hopefully has some ammo. Go through the door that opens quickly revealing three guards. The best thing to do, in my opinion (though it sapps a lot of your power), is to run straight at the middle (and last) guy while shooting. Sometimes you kill him quickly and can turn to the guy on your right to kill him. Keep going amidst all fire and open the metal door. Go inside and stay to the left out of fire. Some guards should have heard your shots and opened the second door for you. Sneak quickly past them and to the left. Shot the guard that's there and another guard will open the door to the lab area for you. Kill him and proceed swiftly up the stairs to the right. Run past the guards that shoot at you (I like to fire a few shots to wound them and buy some time). Once you get through the maze-like hall proceed forward. This is the crucial part -- Dr. Doak. If he's not in this area, then you have to restart. Sometimes he's next to the pillar to the right, or the big lab area to the left, or the lab across from that. What I do is I go in the biggest lab with the four scientists and see if Doaks there. If Doak's near the pillar, he will have seen you and by the time you exit the lab he's there. Anyway, wherever he is, all you have to do is to wait till you say "Time to Leave Dr. Doak." and you'll get when you reach the door. Then proceed down the hall towards the bottling room and switch to mines. At the left turn, there will be two guards. Throw a mine next to them then keep going till you get to the locked door. Blow up the mine and get out the door decoder, which you will have received by this time, and decode it. While its decoding, get out the soviet and turn around and shoot whoever comes around the corner. When the door opens, go down the stairs and run up to Trevalyan. While chatting with him, throw your remaining 3 mines on the floor in between the bottles according to the picture. Run away from the bottles to draw Trevalyan away from the explosion. There'll be someguys firing at you, but just run around to dodge the bullets. Once you get aquainted with Trevalyan, detonate the mines, then run thru the double doors. If you do what I wrote, time isn't really an issue. And if you managed to survive this gauntlet, well, CONGRATULATIONS !!.