This section of the Guide to Control from Remedy studioscontains a description of the Finnish Tango mission.
Searching for Ahti and a visit to the Oceanview
Your task is to get to Sector: Research, and from there, to the Firewall and further to the Ashtray Maze. Soon, you will realize that you can not get through the maze. You must now go to the Sector: Maintenance and go to the Janitor's Office. Unfortunately, Ahti is on vacation. You should try to find him - go to the NSC Coolant Pumps. Using levitation, you can climb higher, to the top area of the site - find the cord and pull it three times.
You'l get to a Motel. Press the doorbell to the reception twice and turn on all the radios in the room on. Press the bell again and do the same thing in the next room. Tap the bell for the last time, and walk through the doors that were blocked. Take the key and open the door to the right of the reception.
Ahti's visions and the Blackrock Quarry
Use the checkpoint - you'll be in the area of Blackrock Quarry. Bypass the location on the left, and head to the beam of light. You get to the elevator - jump down and use levitation so that the character doesn't die when falling.
Now, go to the panel and press the button. There will be a large cloud of enemies that need to be eliminated. After all, enter the railway, which has just appeared, and go into an unknown location
After a cut-scene, Ahti will give you her tape player. With it, you can go through the Ashtray Maze. You finish the job and you start the Polaris missions.