Eighth-grader Olya Tolokondeva receives strange messages on the Internet. Maybe one of her friends wants to play a joke on her? But Olya’s father is a big businessman. Is it possible that an unknown attacker is trying to blackmail him in this way? In this case, Olya is in real danger! However, her new classmate and inveterate truant Fedya Chudintsev, who has never before thought about a career as a detective, is ready to surpass Sherlock Holmes, Hercule Poirot and Commissioner Maigret combined to help the most beautiful girl in the world...