Survive Sevastopol with Prima’s Alien: Isolation Walkthrough.
When you begin the final mission of the game, your objective will be to Escape Sevastopol, then shortly after it will update to Initiate the Docking Procedure. Use your Motion Tracker to locate a terminal that will only work if you Restore Power, then dive into a crawl space by removing the vent cover on the floor to your right. Once inside, follow the wires until you reach a panel, choosing the option to Reboot System. Backtrack out of the crawl space and emerge through the floor, then use your Security Access Tuner on the console that previously needed power.
Your objective will now be to Activate the Guidance Systems, although you may have to bring up your map of the area to see that. You may also get an update about Initiating the Docking Procedure. Either way, use your Motion Tracker to guide you to your next objective, once again approaching a console and using your Security Access Tuner when prompted.
Your objective will definitely switch after that, and your next task is to Engage the Docking Clamp. Follow your Motion Tracker to a Sevastolink terminal, browsing to the Utility folder and selecting the Initialize Docking Clamp command.
Your next task will be to Extend the Personnel Umbilical. Use your trusty Motion Tracker to get you started in the right direction, then go up four flights of stairs to the control room. This will trigger a short conversation with the Torrens, and yet another objective update, this one requiring you to Extend the Maintenance Rig.
The good news is you don't have to go anywhere, just access the Sevastolink terminal and head to the Utility folder, this time executing the command to Extend Maintenance Rig. When that's done, your objective will be to Get to the Airlock.
Backtrack out of this area and all the way back down the stairs, heading to your left where you'll find the airlock. Once you start to get changed, a cut scene will play, and when it's over your objective will be to Get Back to the Airlock.
Start making your way out of the Alien nest, going through the overgrown tunnel when you reach it. Take out any Facehugger scum you might find along the way. It might be a long trip, but it's hard to get lost given that there's really only one direction you can take. Just keep working your way forward, avoiding hazards and looking out for Aliens.
When you reach the area with the transit cars flying by, make your way across the tracks, ducking into the little dips to avoid getting hit. When you spot the Maintenance Office, run inside and hop into the vent, working your way around the right side. You'll get attacked by a couple of Facehuggers, but it's nothing that your Flamethrower can't handle. Exit the vent onto an elevator, then Climb down and out of the shaft. From here, make your way back to the airlock and choose the option to Change. This will also update your objective to Release the Torrens.
Once you regain control, step into the airlock and pass through the door, getting on the lift and choosing the option to Use. When you reach the upper level, follow the catwalk until you get to a trolley, stepping onboard and choosing the Use Button option this time.
When the ride is over, you’ll need to Climb out, then go up what can only be described as too many steps. Once at the top, your objective will be to Prime the Release Mechanisms, so walk around to each one and do just that before being told to Blow the Emergency Release Bolts.
Approach the glowing device on the floor and set each of the release bolts to Active. This will trigger quite the intense cut scene, and when it ends you'll be on your final objectives of the game, Get to the Bridge and Meet Verlaine on the Bridge. Start making your way there, following the on-screen prompts and enjoy the ending.