A Soviet scientist creates a brilliant robot. This is a boy who is able to solve any mathematical problems, he writes the best essays and sings perfectly! And he is also an exact copy of schoolboy Seryozha Syroezhkin. A clever boy quickly shifts all his duties to an electronic double. He does his homework for him, goes to school and does household chores that his parents entrust to Syroezhkin...

A classic mystery based on "The Face in the Target" story by G.K. Chesterton.