Survive Sevastopol with Prima’s Alien: Isolation Walkthrough.
Your objective to start the mission will be to Return to Taylor with Medical Supplies, so walk toward the fire and climb into the vent on the left side of the corridor. This will update your objective to Find an Alternate Elevator.
There's only one way you can move through the vent, so follow it until you drop to the floor below, receiving a new objective to Find a Compression Cylinder to Repair the Elevator. You might also want to save your game, but that's completely optional.
Make your way along the corridor and hop into a vent on the right side of the wall. Follow it to the only exit, emerging with three humans just a few feet to your left. Walk forward until you spot a vent cover on the floor, removing it and dropping down inside.
When you enter the vent, turn all the way around and crawl forward, turning right when you can't go any further. Follow that path until you hit another right turn, then take a left when you reach an open area. Continue forward until you have to go right, climbing up out of the ventilation system next to a ladder.
Head up the ladder and turn to your right, following the corridor until you reach the second open room on the right, grabbing the Smoke Bomb V.2 from the wall and saving your game. Exit the room and turn to your right, following the hallway until you see the door with the Synthetic Storage sign above it, then head inside.
Walk through the corridor until your objective updates to Find a Way to Open the Door to the Warehouse, then continue moving forward until you pass into a large room. This will once again update your objective, this time asking you to Use the Requisitions Android to Access the Components Warehouse.
Approach the Synthetic that is idol inside the glass case, updating your objective for a third time in about 10 seconds. This time you must Find a Way to Power Up the Requisitions Android. From your position looking at the Android, turn to your left and walk to the far end of the room, heading through an open door and saving your game with the mechanism on the left wall. Picking up the device on the table will give you a notification of Security Access Tuner Upgraded.
Exit that room, walking along the wall on your right until you reach the door you originally used to enter this area. Exit back into the corridor to find a ladder, climb it, move forward and choose the option to Use Security Access Tuner on the console in the room. This will provide you with a new objective to Activate the Requisitions Android at its Booth.
Leave the room, passing by the ladder and using the Security Access Tuner on the door to the right. Head inside and loot up, then use the Sevastolink terminal to view the Shared folder, and more specifically the message Elevator Out. This tells Ripley (that's you) that if she doesn't want to use the Requisition Android to find the parts to fix the elevator, she can find them herself in Components Storage - Row 1 - Stack B. it's completely up to you how you want to approach it, but doing it yourself requires a Keycard, so we decided to fire up the Android instead.
Depart the room and head back down the ladder, going into the room with the idol Requisition Android in the glass case. Walk up and press the button to active it, updating your objective to Retrieve the Compression Cylinder.
Follow the Walking Joe (Requisition Android, Synthetic) until he leads you into the Components Storage, but instead of letting him lead you once you're inside the room, approach the stack on the right and choose the Move Down option four times. This will allow you to shimmy to the other side of the storage without getting electrocuted like your Synthetic friend a few moments ago.
Once you're on the far end, head over to the stack that the Synthetic was leading you to and choose the option to Move Down. This will allow you to collect the Compression Cylinder, updating your objective to Replace Component in the Elevator.
Exit the Components Storage room and turn right, following the corridor until you pass through a door. Turn to your right this time, heading into the area just beyond the Technician Training sign up above. From here, it's a straight shot to the elevator. When you arrive, choose the option to Replace Compression Cylinder, then hop on and press the To Synthetic Fluid Plant button.
After a short elevator trip you'll arrive at your destination, getting a new objective to Find Exit to Synthetic Fluid Plant. Head through the door in front of you to a room with a hanging assembly line, moving forward along the left catwalk. We're not sure about you, but it was about this time the Alien dropped in on us, but like the champions we are, we just moved forward and into the Facility Administration area.
Once you pass through the door, turn to your left and follow the narrow corridor as far as you possibly can, going through another door where you'll find two people with guns. Sneak past them using the desk as cover, exiting the room on the opposite side from where you entered. Keep moving forward until you reach an elevator, choosing to send it To SCIMED Tower Transit. This will update your objective to Get to Sevastopol SCI/MED Tower and bring the mission to a close.
Continue to Alien: Isolation - Mission 8: Haven.