Criminal investigation is investigating the case of robbery of the factory cashier. At the checkpoint of the factory of precision mechanics and optics, two criminals attack the cashier. Criminals manage to escape by the car, waiting for them around the corner. At the scene of the crime, criminal investigation officers arrive Major Dorokhov and Lieutenant Matushkin. They interview witnesses, but they did not remember properly any attackers or machine numbers, but noticed that one prevented the other from firing.
In the wealthy noble family of Popelsky, the only son Petrik is blind from birth. His mother Anna Mikhailovna, infinitely loving and pitying the boy, educates him as a rare fragile flower. And only Uncle Maxim, who fought under the banner of Garibaldi in his youth, is trying to accustom the boy to independence. The boy begins to recognize the world by touch, and one day his fingers find the keys of a piano. But, still not knowing the price of his talent, he leaves with the tramps "to seek the truth." And now only love can reconcile him with the world of the sighted.
