To escape from the first room you’ll need to open a bookshelf door. It will open if you take a certain book from it. The name of this book is given on a sheet of paper which you can find on a table(I placed it under a lamp to make it more noticeable).
There is also a book cipher on it and you must use it on the same book that opened a door. Then you will get a word, encrypted with a Caesar cipher. If you’re not familiar with book cipher and a Caesar cipher, don’t worry! There is also a little hint in this room - a book about ancient ciphers, where you can read about the ones you will need in this game.
In the next room you will find a small discharged device with a solar battery. To turn it on you’ll have to put in on the table which stands in front of a window. Then you will get a second word, encrypted with a Caesar cipher. The third word is written on a piece of paper hidden behind a mirror in the bathroom. Then you’ll need to type all three words into a device with a screen and a keyboard, which stands in the corner of the second room.
The last thing you have to figure out now is a key to decrypt the words(the device has a shift button, so it will do the decryption for you). You can just press the shift button until the device gives you a code, but there’s also a hint - the device’s name is “Caesar 7”, so the key is 7. And finally, when you get a code, you’ll be able to unlock the exit door.