GoldenEye 007 on Nintendo 64 - 00 Agent Mission 6: St. Petersburg - part ii: Military Archives

1. Escape from interrogation room
2. Find Natalya
3. Recover helicopter black box
4. Escape with Natalya

It's on 00 Agent difficulty that you unlock the Military Archives cheat code, and it's not an easy one.

a. Escape from interrogation room

The guard on the right has the key. Personally, I prefer not to pick up the gun on the table, since the guard lets you approach if you're unarmed, and a good punch in the face works just as well. You can kill both guards this way. In general, it can be a good idea not to shoot in this level, especially from Secret Agent difficulty onward. Once you have the key, take the door.

b. Find Natalya

Objective "c" (recovering the black box) is quite tedious if Natalya (and too many guards) are following you. So I'd recommend rescuing Natalya afterward. Leaving the interrogation room, go right and take the staircase at the end. At the top of the stairs, turn left and go through the door at the end of the corridor. In the opposite corner of the large "mezzanine" room, take the door at the far left, up the stairs. In this other large room, go straight ahead and open the small door located between the two big ones. Somewhat surreally, Natalya, held hostage and even at gunpoint with a guard behind her, shouts "James" and joins you.

c. Recover helicopter black box

Leaving Natalya's cell, go straight ahead and take the double door on the left, then go down the stairs. Follow the wall and take the door on the right. Immediately go left and follow the wall to take the door almost directly ahead, then the one right after on the left. Mishkin is waiting for you; he has checked your story, Ourumov is a traitor, and he's going to alert the authorities. He gives you the key to the safe so you can open it and recover the black box that will let you prove Ourumov's guilt.

d. Escape with Natalya

If you did Natalya's objective last, leave her "cell" and take the double door "opposite" to the right. Directly ahead are large windows; shoot them and go through once they're broken. If Natalya is with you in Mishkin's room, take the door opposite the safe and follow the corridor. In the room at the far right, you can break a window and escape.