The game may seem difficult to understand, so I decided to leave a walkthrough comment.
Caution, spoilers!
1. First, you need to find 3 "rubies" scattered in rooms resembling hotel room numbers.
- The first ruby is located in the room opposite to player's room. The ruby is lying on the table.
- In the central corridor, the central room is on the right side from the elevator. On the floor, near the wardrobe, there is a box containing the second ruby.
- The furthest corridor from the player's room (the player's room is where the music plays). The central room is on the left side if you are facing it from the elevator. There is a box on the table, and inside it, there is the third ruby.
2. After you've collected all three rubies, you need to get caught by the security guard who walks along the corridor at least once. He will offer you a pill. Choose "Fake" when prompted.
3. Next, go to the room with the statue. Give the statue the three rubies, and you'll receive the key to the secret door.
4. Proceed to the next room with paintings. Consume the pill from your inventory that the warden gave you. Rotate the paintings so that the total number of people in them adds up to 10.
5. One of the bookshelves will disappear, and you will be able to open the secret door with the key you found earlier. In the room, there will be documents on the floor and a key to the elevator. Take them and run to the elevator.
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