Deus Ex: Human Revolution/In the Belly of the Beast

After speaking with Keitner, you'll have a new objective: to upload your biometric information into the mainframe computer. As a side quest, you can also go talk to her friend Quinn to get some inside help.

Upload your biometrics
Before you leave, if you've upgrade your hacking for turret domination, you can use the unlocked security terminal by Keitner to disable the turret outside, although it's not really necessary. Your next objective is through the maze of halls to the south of the loading bay, and you can get in there in a couple places. One is through the doors on the ground floor behind the turret, and one is up on the walkway on the east side of the bay. If you take the upper entrance, you can find the code to the door on the guard up there, although it's only a level 1 security panel, so you should be able to hack it regardless. When you get into the halls, you can roam around and explore the offices to find items and get experience points. There are a lot of vents connecting the offices together and leading under stairwells also.

Here is some quick info while exploring the halls:
 * The northwest office on floor 1 (Army Operations), has a vent you can use to get across the hall into the locked Special Operations office, where you can get a code to the Communications Security office or bust through the wall to get to it.
 * The Logistics office with the level 1 security lock on the east side, first floor has a vent that leads across the hall to the office behind the lasers. There is an unlocked security terminal in there that shuts off two annoying cameras.
 * In the unlocked Protection Service Division office next to the southeast stairwell, there is a pocket secretary with the code to shut off the lasers.
 * The Communications Security office has a silencer upgrade in it.
 * The panel to shut off the lasers is located in a hidden room accessible from a maintenance tunnel with a level three security panel in the far west hallway, or from the vent in Burke's office upstairs.
 * In Burke's office upstairs, you'll find a spare retinal prosthesis that you'll use later, and a hidden button underneath his desk that opens a secret safe. The vent also leads to Keitner's office.
 * In Keitner's office you'll find a damage upgrade.
 * There are two stairwells you can get under, one is accessed from the men's bathroom in the northeast and one is through the vent in the Protection Service Distribution office in the southeast.

When you're done exploring, head down the southmost passage and into another security checkpoint. On the other side you'll find yourself in a large cylindrical room that goes up three stories. In the center is the tower where you can upload your biometrics so you can pass the security checkpoints into the restricted zones. When you first come into the room, you'll find one guard alone on the west side and two together on the east. You'll be coming back through here, it pays to take them all out while you're here. One of them has a pocket secretary with the security terminal password on it. When you're ready, go down to the very bottom of the room at the base of the tower and use one of the vent covers to get inside. Once there, you can take the ladder up, which puts you behind the guard up there for an easy take-down. Upload your data to complete the objective.

Investigate the interrogation wing
Now you'll need to start heading up a couple stories to the next checkpoint. On the second floor are a couple bots patrolling both sides of the bay, so if you have robot domination upgraded, you can shut them off from the security terminal next to where you uploaded your biometrics. If not, you can take them out using conventional means, or just avoid them with stealth. There are laser grids on both side of the second floor, and the panels are security level three, so you'll need upgraded hacking and probably some time so the bot doesn't come around and spot you. If you're doing a no Praxis run, you can follow the bot through the lasers instead. When you get up to the second floor, follow the bot on the right and go into the cell after the lasers to hide until the bot passes back the other way. If you're not close enough to make it through the lasers, you can wait and hide behind the boxes on the east side and try following the bot again when it returns. There are also walls you can punch through in the open cells on all floors, and they lead up and down between levels.

On the third floor is a new security feature, the laser turret. This defense system spins around with short-range lasers shooting out to two sides. If you trip the laser, the turret will fire its rounds off in a 360° spray, just like your Typhoon upgrade. It moves slowly, so you should have no trouble following one of the lasers around. You can jump from the ledge next to the northern turret out on top of the tower for some experience points and a Praxis kit. If you don't have legs upgraded to jump back up, you'll have to rely on the Icarus landing system to get you down safely. At the southeast corner of the third floor you'll pass through another checkpoint if you completed the previous objective of uploading your info into the mainframe. After the checkpoint is a dark hallway going over some torture chambers. For some backstory, check out the audio log in one of the rooms on the side. When you get downstairs, you'll talk to a remaining prisoner who begs you to help her. Unfortunately it wouldn't be safe to let her out just yet, so you'll need to continue on. At the end of the passage you'll run into Burke and a couple scientists, who will take a secret elevator down out of sight.

Give Burke's eye to Quinn
Burke used a retinal scanner to access the elevator, and in order to trick the system you'll need to take the retinal prosthesis you swiped from his office to Quinn to rig a fake eye. You'll have to backtrack the way you came, all the way through last the two checkpoints. When you get back into the hallways after the second passage, be back on high alert, as there are more guards around since you left. There are two guards in front of the elevator that goes down to Quinn, so it's probably easier to just take the vent, which is in the middle of the middle east-west hallway. Talk to Quinn and you'll get your jury-rigged eye. Now you have to go all the way back up to where Burke used the scanner so you can follow him down in the elevator.