Non-lethal ammunition is very important in the CIA HQ. You need to conserve it as best you can. The following steps start at the first place you should use it: After you enter the weapons room and disable the turret gun, take the elevator up and save at the checkpoint. Enter the room directly ahead of you. Once you are inside the room, stick to the right wall and sneak around back of the guard sitting at the computer. Behind the desk is a walkway which will allow you to sneak quietly around the room without confrontation. When you get towards the back door, wait for a guard to leave and then creep into the next room towards Daugherty's office. Once the area is clear, begin your walk towards the security camera at the end of the hall, then save the game. Wait until the camera turns away from you and use the first of your non-lethal ammunition (either the sticky shocker or foil ring) and knock out the guard sitting underneath the camera. When the camera turns away again, run underneath it and take aim at Daugherty, who is working with the soda machine. Shoot him with your second non-lethal weapon. Your headset will tell you it is a mistake, but it is easier this way. Drag the guard from the chair back to Daugherty's office --beware of the camera. Once you have hidden him. go back to Daugherty's body, again mindful of the camera. Grab his body and make your way for the door at the end of the hallway. Keep to the right side, crouched so that you can sneak past the break room window and then down to the keypad door. The code is "0614". This will bring you out to the smoking area, where there is still one guard out on the terrace. Again, use non-lethal weapon to knock him out and then hide his body. Then, pickup Daugherty again and bring him down to the next door and your final checkpoint. At this point you should have more than enough ammunition to shoot the four guards and the engineer non-lethally and easily escape the level.