1. You find yourself at CIA Headquarters in Langley, Virginia. Your immediate objective is to enter the building through a temporarily-stalled ventilation unit in the indicated area.
2. A timer counts down, as the ventilation unit will soon reactivate. Your quickest approach is to shadow this guard across the main driveway.
3. Scurry to the fenced-in area ahead.
4. Scale the fence where the barbed wire is missing.
5. Double-jump off the left wall to the ledge above.
6. Slide open the lower right panel.
7. Pass through before the timer runs down.
8. Drop over the catwalk to the floor below.
9. Climb over the fence.
10. Pick a good dark hiding place and the guard won't see you.
11. Time your approach to these stairs to avoid the security camera.
12. Beware of the guard above you. Ascend the stairs once he has his back turned.
13. Keep the guard's back to you as you sneak across to the other stairs.
14. Go through this door on the right.
15. Use the computer to get a data stick. Note the medical kit on the corner of the table. You'll find a ring airfoil round and a sticky shocker there too.
16. Exit through the opposite door. Wait for the guard in the window to turn away then pass through the indicated doorway.
17. You can grab this guard while he's distracted on his cell phone. Hide the body behind the marble divide to the right.
18. You'll find a soda can on the bench next to this guard. Toss it to create a distraction.
19. Take the elevator down.
20. While this employee is in the copy room, sneak to his office on the right.
21. Access this computer to learn that the Main Server room code is 2019.
22. Turn left to Security Station A.
23. Enter the security station.
24. The guard is on the 16th hour of his shift. You can easily knock him out and take his satchel.
25. Pick this lock to find a storage cabinet with a medical kit and two sticky shockers.
26. Exit the security station and backtrack. This is a good dark spot to hide in while the guard passes.
27. This time head for the Server Room.
28. Sneak past the window while this employee's back is turned.
29. Grab the keypad maintenance technician and knock him out in the nearby closet. You'll find a disposable lock pick in there, too. Switch off the light to conceal the body.
30. Knock out this employee and put his unconscious body with the maintenance technician. Grab his satchel to learn that the keypad code is 7687.
31. Approach the keypad while the guard is isn't looking. Enter the code you obtained before - 7687. Before entering, use your optic cable to make sure the men inside aren't facing the door.
32. You can grab this guy or just sneak past him. Continue through the doorway and take the medical kit on the wall.
33. Use this computer to learn the Backup Battery Power room code - 110598.
34. The Backup Battery Power room door is just to the right. Enter the code 110598 to enter.
35. Descend the stairs and knock out the two employees in the battery room.
36. Continue down this corridor and up the stairs.
37. Here you'll find your SC-20K, a sticky shocker, a sticky camera and a ring airfoil round.
38. Exit down the hall to this break room, where you'll find a medical kit. Avoid the employee on the cell phone.
39. Continue toward the Server Room.
40. Take this guy out with a sticky shocker.
41. Hide the body in a dark area around the corner.
42. Now you can head to the Server Room without having to check your back.
43. Pass through the blue Static Dispersion Chamber and enter the code 2019 on the right keypad. (The code works on both keypads but the right entry is stealthier.)