The Underground Lab starts immediately upon arrival. You will reach this area via elevator, and the new objective will pop up instantly. Walk forward into the main lobby. Record the screens above the desk to get a Note entitled “Under the Mountain.” Walk around the desk and pick up a Document entitled “The Pride Of Wisdom.”
Go through the doors on the right into the A Block hallway. The last lab on the left (A004) holds a Document entitled “Variant Postmortem.”
Continue down the hall until you see a side passage with a green light over it. This passage leads to room J666. Record the whiteboard with the formula to get a Note entitled “Morphogenic Formula.”
As you make your way towards the end of A Block, you will come into contact with the Walrider again. Unlike before, this time around he will attack. Turn around and start running the other direction as fast as possible. Make it to the end to initiate a short scene. You will get a Note entitled “Death Of The Soldier” at the conclusion.
Turn around and enter one of the newly opened rooms (A002) towards the start of A Block. Enter and listen to the dialogue. You will get a new objective immediately after.
Find Billy in the main laboratory.
Exit out of room A002 and take a left down the hall. Another door has now been opened, which leads to B Block. The Walrider will return around this area, so stay on your toes. Follow the “Morphogenic Engine Chambers” signs if you get lost.
When you reach a room with a large staircase and orange vats, go along the right side and squeeze through the space between the vats to reach the stairs. Climb up the steps and enter the decontamination chamber at the end.
Exit the decontamination chamber and take a right to the next room. A Document can be found on the desk near some dead guards. This Document is entitled “Gods And Monsters.”
Continue along the halls towards the main laboratory. Upon reaching it, record the large structure on the ceiling to get a Note entitled “Wernicke’s Machine.” A new objective will become available.
Turn off the valve for the LIFE SUPPORT FLUID RESERVOIR.
Walk towards the large machine to find a Document near some controls. This Document is entitled “Morphogenic Engine Chamber Precautions.” Record the man in the bubble to the left to get a Note entitled “Billy Hope.”
The first task is in the Life Support Fluid Reservoir to the right. Follow the hall to a large room with a few tanks. Record these tanks to get a Note entitled “Life Support.”
Climb up the staircase in the back and grab the Document in the small control room. This Document is entitled “The Modern Prometheus.” Interact with the valve at the end of the catwalk to shut down the system. A new objective will instantly become available.
Cut off the electric supply from the SUBLAB GENERATOR.
While making your way back to the main lab, the Walrider will make another appearance and attack. The Sublab Generator is located on the other side of the huge machine in the main lab room.
After climbing up a number of steps and running through a hall or two, you will come to a large gap on the catwalk. Jump across the gap and take a right into a dark hallway. At the end of the hallway is a Decontamination Chamber.
Through the chamber is another flight of stairs, and at the top is a Document on a desk. This Document is entitled “Permission to Proceed.” Interact with the generator to the right of the desks to complete this objective.
Disable Billy’s Life Pod failsafe.
Return to the main lab as quickly as possible. Interact with the control next to Billy’s Life Pod to disable the failsafe. After a short cut scene, record Billy’s Life Pod to get the final Note entitled “Death Of Hope.”
The final objective is to escape. Turn around and walk up the stairs towards the exit. You will be limping, so it’ll take awhile to reach the end. After a short ending scene, the credits will roll.