The android robot Electronic escapes from Professor Gromov's laboratory, like two drops of water similar to a boy from the magazine cover, whose appearance was used by the professor when creating Electronics. The resemblance to the "prototype" is absolute; the only external difference between Electronics and a living person is the lack of emotions, in particular, the inability to smile. Randomly, the circumstances develop so that "doubles" meet.

At the same time, "somewhere abroad" there is a gang of criminals headed by criminal authority Stamp. He instructs Urri, the best gangster of the whole gang, to find and steal the Electronics, which is needed to participate in the "crime of the century" - the robbery of the city art gallery. Urri on a motorcycle arrives in our country to perform the responsible task of his boss.

Sixth-grader Seryozha Syroezhkin, whose credo is to live for his own pleasure without straining, quickly sags and takes his double - Electronics into circulation: he offers him to go to school instead of himself and even appear at home, convincing him that this is how he will "become a human" (becoming a person was No one can distinguish Electronics from Sergei. The robot has friends. Teachers cannot rejoice at a capable student who suddenly showed unprecedented talents in mathematics, physical education, drawing and even singing. Sergei's parents are also unaware of the substitution and only rejoice at the success of their pseudo-son...