Avak-37 - the planet of the first Cosmo-Frogs is in danger! Time is short, and the real Heroes of the Frog People - Dreamko and Princess Kvara are in a hurry to help. In search of answers to the mystery of the witch, they find themselves on the colorful Cosmo-Cats planet Ruduk. There are many surprises and adventures waiting for them: the underground city of Cosmo-Cats, the crystal golem Kotun, the magician Kvarlin, a lot of magic and technology and the first of three secrets - the mystery of the Cat King's black crown.

The book is very good and funny. It teaches children mutual support, the importance of a healthy diet and respect for the environment.