Find The Sally Port
Approach the door on the other side of the CIC. Wait for the guard to move into the CIC, which he will do if you open the door, and take him down. Loot for a grenade and a credit chip. Now look at the floor around the CIC console. You will find a pocket secretary with the access code for the security computer on the opposite side. Head over there and use it to turn off the two cameras farther to make your life much easier in the future. That code is: A12E11BK
When the guards are facing away, head down the stairs and go into the nearby corridor. Slip into the nearby grate to get a credit chip. Head back to the corridor you were in and go to the left. Just head forward now to the marker in front of you.
Head on down the stairs. Keep on going down until you reach the bottom and can see a ladder in front of you. Head to the left, over to the door, Open it up and head through quietly. There is a pair of guards down the corridor. Creep along the right-hand side of the corridor and listen to the dialogue between the two soldiers. Once they finish talking creep up behind the one that has passed up you by and take him down. Quickly drag his body back into the room with the ladder then loot it, if you are going for stealth. Among the items is a pocket secretary with the access code for rooms B-01, D-01 and CMPT-04: 1094. Now slip down the corridor and take down the other soldier who is caught up in a game. Take him down, and move the body so it is not visible from the door you are about to open. Open up the door nearby where the guard was.
Inside this room check out the lockers to the right to get a Stop virus. Now head forward and out the door to the left into the next corridor. You will find your way over to a ladder which is guarded by a fluctuating laser grid. If you feel confident, you can try to slip down the ladder in the gaps. You can also get the access code from one of the nearby guards. Creep past the ladder and get in position to quickly take down the guard nearby. Wait for the other guard to turn their back then take the first one down. Quickly drag the body into the corridor you are in. Now wait for your battery to recharge then take down the second guard to get the laser grid code: 9173.
Head on down the ladder. You can duck very quickly in the gas room and live but it has to be fast. Now turn around and take the elevator downwards. Once there, head out to the left and climb over the crates to reach the bottom deck. Duck and head into the next hold. After the dialogue between the two guards wait for one to move away then wait for the second one to move. When he does, he will drop a pocket secretary with the laser grid code between where they are and the sally port, your destination. It is: 6834.
Head forward and take down the guard who was in front of you. Now head toward the back of the room. Time your movements carefully to make it all the way through without getting seen. On a server cabinet to the left of the laser-guarded door you will find the terminal you need to put the code into to access the room beyond. Wait for the guard and camera to face away then head on through the door.
On the other side, slip to a side until the door closes then go for the back right door. Head on through and go to the door around the corner. Interact with the controls on the left and then step into the Biometric scanner. You will encounter your support person again who will get you through the security. Time for the next part of the mission.