If you don't have passed yet, i will tell you how to do. First go to the entree for the HQ wiht the red lasers, use your starkey to turn it off. Enter it. When you enter it, go in the elevator, you will do this now alone, HH wil leave you. Now, you see one AS guard above there, to get past hem, you must crawl under the bridge, you have passed him, There is another AS Guard , don't worry, as long you don't walk to him, but walk away, he will not see you. Go to the ladder, let jade hang, do not go above, you see 2 AS guard. One just stands, the another one will walk, now you just wait until the AS guard that walks walk away from you, quickly go up, and then lean to the wall right for you, wait until the AS Guard come back and then agin go to walk. Quickly crowl to the next wall by the rigt side. Wait until het walk back, he will not see you, then walk right where he came from en climb the ladder, The AS guard left will not see you, so don't worry, now, you will see two AS Guard, one just stands, one just going to scan the are wiht his eyes. Wait until he look away from you and jump to that ladder under you, by the blue lasers. Wait again until he look awyas from you, and quickly pass him, you will see if you passed him a box, climb it up and sneak to the windows, wait always until he look away from you and continue to the other windows, when you are inside, use your key to enter the door right from you. Then continue, The Alpha sections will chase you, just continue walk away from then, and you have done this mission.