1. The important thing to notice with the loadout options is that Redding's recommendation and the stealth option include two flash grenades.
2. Three guards patrol the immediate area. Hug the left wall to stay in shadow. Move slowly as the three lanterns on the wall are motion sensitive. (Note that a valve across the yard can be used to activate the sprinklers and disperse the guards if you like.)
3. Throw the circuit breaker to disable the front lights.
4. Wait in ambush for the guard who investigates. Interrogate him to learn about the motion sensors.
5. After a moment the second guard investigates. Knock him out and place both bodies in the dark corner. Repeat on the third guard. The yard is now clear.
6. Avoid the third patrol then pick the lock on the front door. The darkness conceals you from the security camera visible upper-right.
7. Opening the door illuminates your surroundings. Note the camera above the receptionist. Quickly enter the building and scurry into shadow.
8. The receptionist investigates. Play cat-and-mouse with him until you can grab him from behind. Interrogate him to learn that there are about 20 guards on duty - 16 after you knock him out.
9. Close the front door swiftly to avoid detection by the cameras. Use this computer to learn about a medkit in the first floor bathroom. Also learn that the security code for the first-floor security booths is 3624. Take a look at the security camera images as well.
10. Next, select "Security Access."
11. You are presented with a list of IP addresses. The display on the right will light with the correct octet for the IP you are trying to hack. Click on the number as it's lit and the wrong options are removed from the list. Wait to see all four options illuminated, or until you've eliminated all wrong options. Guess wrong or use up all your time and an alarm will sound.
12. Click on the correct IP and this new option appears, "Upload Fake Email." Select this to update your opportunity objectives.
13. Secondary fire from your SC Pistol disables the security camera long enough for you to slip back out through the front door. (If the door to the teller area is open, you may continue through there.)
14. Follow this path to the well-lit right side of the building.
15. Disable this security camera then climb the ladder far-right.
16. Grimsdottir suggests you look for a junction box to power down the dome windows' magnetic locks. Pick the lock on the indicated door.
17. Use this panel to disable the magnetic locks - and activate a laser grid.
18. Approach the far side of this open dome and choose "Grab onto rope" to descend.
19. This part looks cool, but why in the world is there a rope hanging from a bank ceiling? Talk to Turtle to learn that you need to authorize the vault access from three separate panels. Note the laser beams activated below.
20. Secondary fire from your SC pistol will temporarily disable a beam. You can also access any of the computers to deactivate the entire field.
21. You can also activate your EEV vision (default "1") and let your crosshair linger over the computer. Pressing the use key key will access the computer, letting you disable the grid remotely. (Hat tip: Phil Donahue.)
22. Slip out of the teller's area and approach this door. You can either grab the sleeping guard and use him to activate the retinal scanner, or you can hack the retinal scanner - my preferred choice. Continue through the door on the right.
23. Quickly hug the right wall to avoid the security camera above the Exit sign. The door on the right can be ignored for now -- it leads to a hallway which ends up at the door by the ladder you used earlier. Also ignore the door on the left -- we'll be back later.
24. Move quickly to grab this guard before he moves on to the security station. Knock him out in a dark corner. The guard working on the keypad ahead will mumble the keycode to himself, 8645. You can also interrogate him to get the keycode. Knock him out or wait for him to move away from the door.
25. 8645 gets you in.
26. This is the treasurer's office. Use this panel to enable the first of three authorizations.
27. Search this cabinet to update your secondary objective, "Look for any suspicious transaction records." Hack the computer to upload your second fake email.
28. Exit the room then quietly approach the security office across the hall. 3624 gets you inside.
29. Quietly enter the office and grab the guard farthest from you. Take him out to the hall and knock him out. I was consistently able to take out this guard so long as I grabbed him first.
30. This second guard is a bit more skittish. Grab him from this position seen here. Take him out to the hallway and put his body in a dark corner with the others.
31. Access this computer to read some background, view security cameras, and send your third fake email.
32. Slip outside and use your OCP to disable a camera to the right of the doors.
33. Overhear an enraged guard reveal the door code to the president's office - 3490. Interrogate the patrol to learn the back door code 3901. (Two alternate paths are nearby: A pipe just off-shot to the left leads to the roof, and a crawlspace to the left of the door leads to the treasurer's office.)
34. Backtrack to the Exit sign. Disable the camera with your OCP. This gives you enough time to pick the lock on the door opposite.
35. Enter this crawlspace.
36. Hold here. Don't exit the crawlspace until you see this guard enter. Note the medkit you learned about earlier.
37. Something about the Splinter Cell series and peeing guards. (See here and here.) Interrogate this guard to learn about the security camera control room on the second floor.
38. Open the door then disable the security camera across the hall with your OCP. Again, 3624 unlocks the door.
39. If you move quickly (and silently) you can grab the guard from behind before he turns around.
40. Access this computer.
41. Upload your fourth fake email and Lambert confirms there are four more to go. Read "RE: Security Room Door Code" to learn the main security room code 2306.
42. Exit the room, remembering to disable the camera above the door.
43. Turn left to continue through this door.
44. Ascend these stairs, careful to avoid the guard at the top. Use this camera angle to spy his location before you advance.
45. Grimsdottir reveals that the guards possess beacons that deactivate the laser beams. Shadow this guard and you can get past the grid.
46. Better yet, knock him out and carry his body around as needed. Access this computer to send fake email number five.
47. A second guard patrols around the next corner. As he heads left, you should head right. Continue left as he returns.
48. Ditch the body and turn right into this room. Beware the security camera on the left wall. Slip behind the curtain in the far-right corner.
49. This is the main security room you learned of earlier. Enter with the code 2306.
50. Just as before, it's easier to take out the guard on the right first. Interrogate him in the hallway (leave the door open as you enter so you can get him back out) to learn of a vent that connects the security room to the outside. This is an alternate entrance to the second floor, accessed by the courtyard pipe.
51. Grab the second guard and knock him out. The panel seen on the left enables the second of three authorizations for the main vault. Use the computer on the right to delete the camera archives and disable the camera system.
52. Use the computer the second guard was using to deactivate the ceiling fan and upload your sixth fake email.
53. Around the corner is the president's office. Enter with door code 3490.
54. Ignore the outer office. Instead, pick the lock to this office then hack this computer to send a seventh fake email. Use the panel on the wall to enable the third authorization for the vault.
55. Exit through this open window then drop to the ground below.
56. Re-enter through the back door, code 3901.
57. This door near the first security station is now open. Enter and make an immediate right.
58. Open box 1024, found in this corner. Pick up the supplies and head down to the vault.
59. Here's the vault. Two locks are found, one on each side of the vault door. Place a telemetric lockpick on one, then pick the other lock yourself.
60. Follow the instructions to simultaneously pick both locks. Basically, wait for the red light to turn green before proceeding to the next pin.
61. Place a charge on the vault door, then back away. When you are a safe distance from the vault, detonate the charge.
62. A most-impressive vault opening ensues.
63. Access this computer at the back of the vault.
64. Upload your final fake email, then choose "Open Cage."
65. This compartment opens behind you. Grab the $50 million to complete the objective.
66. Everything's done but the exfiltration. Don't be in a rush to leave the vault, though. Activate your thermal vision to spot a laser across the vault opening. Use your OCP to disable it before leaving.
67. Lambert radios that the exfiltration point is in the same spot as your dropoff point. Backtrack to the exit sign, this time actually using the door.
68. Follow the hallway then emerge here, on the side of the building you visited at the beginning of the level.
69. Work your way across the yard then find this spot on the wall to exfiltrate and end the mission. (For thrill seekers, a pipe on the right/front side of the building leads to a zip line which will place you at the wall.)