The “Cool Detective” series began with the works of Katya Matyushkina about Da Vinci the Cat. Later it included funny detective stories with fantasy elements for children 6-12 years old. These are stories about brave cat detectives, scientists-inventors of unimaginable devices, children with unusual abilities and other characters with super intelligence and super strength. The stories in this series are distinguished by the incredibly fast development of events; their plot is usually built around mysteries that have worried humanity for centuries, and these riddles are solved by superheroes and their friends. The books have a large number of bright illustrations.