But our main character is a city boy. University professor Antos loses his faithful friend, the beagle Argus. At the same time, his wife decides that their marriage has exhausted itself. Looking for a hobby to occupy his mind, Anton agrees to help his friend and decipher the text of mysterious notebooks found in an attic in one of the villages near the Abyss - the swamp near which the main character's grandfather lived. The notebooks are written in Sütterlin, a now forgotten German script. Only individual words are legible, but the more the hero understands, the more anxiously he looks in the mirror.