Life in the town of Primorskaya Adost is full of mysteries, and the main one is the ancient legend of the evil monster.
At the coastal hotel 'Grand Nautilus', twelve-year-old Herbert Limmon serves faithfully as the lost and found caretaker. He returns lost or forgotten things to guests, but one day Violetta appears in his closet and asks for help in returning... her parents, who have gone missing in these parts.
How is their disappearance connected with the evil monster? Why are the local collector of marine curiosities Mrs. Ammonite, the museum curator Dr. Laminario and the famous writer Sebastian Minogue so interested in a ruby-colored glass bottle? And what does the imperious Lady Kraken, the owner of the hotel, see in her moon chamber?
If you are ready for incredible adventures and fascinating reading, the mechanical fish-monkey in the book pharmacy will definitely prescribe you 'Evil Monster'!