Go on top and enter the server room where the ghost came from. Here you will need to start the generator. First, press the button on the left until the green light is on. Next, enter the code that is displayed in front of you (number the keys from left to right from “1” to “3”). The second green light will come on. And then pull the lever.
Go down. There are several doors leading to different apartments. Please note that the passage to the wing of GAMMA is blocked by electricity. Next to him there are a lot of chess boards, and you find the first collectible key card from apartment V. Steinitz on one of them.
Climb up the stairs nearby, walk behind the reception desk and remove two key cards from the wall - from the fire and wind apartments. Open these doors in the corridor nearby. There is the first photo on the bed in the room with balloons. There is a note of Einstein's passport in other apartments, but they are not collectible. Enter the closet next to the board with the code combination - 33212. Memorize it. Perhaps in your case there will be a different code.
Go back down to the aisle with electricity and go right. Turn right and see a locked pantry and lots of blood. Climb the metal stairs to find the second photo near the corpse. Go to the steps opposite, climb up and jump over the bollard on the right. Look at the apartment wing to see where Ada’s apartment is located.
Ada will contact Rose and tell you what to do. There are spare keys in the GAMMA wing, but the path is blocked by electricity. Therefore, you need to disable it. That code is useful. Go back to the aisle with electricity. By the way, you can pre-pick a photo in the fountain on the ground floor in the opposite wing, not far from the door of the monorail station (or rather, there are not doors, but lattices).
To be continued...