The young Chinese peon Van, staying in an overnight house, becomes the casual victim of a recruiter. He is dressed in a soldier's overcoat and given a new rifle. At the same time, at a Soviet frontier post Red Army soldiers Vaska (Melnikov) and "Malyutka" (Nazarenko) are learning Chinese phrases about class unity with the peasants of Manchuria. Next, Quomintang soldiers with White Russian officers seize the Soviet border village. The wounded Red Army man Melnikov falls into their hands, and the young soldier Van, like the others who took part in the raid, witness the cruel interrogation of Vasily by Captain Alyabyev (Zhakov). The Chinese army begins a direct invasion of the USSR with an attack on a border bridge. At the cost of their own lives, several Red Army men hold positions. A massive counterattack by the Soviet troops rejects the enemy. Among many Chinese soldiers, Van is taken captive. After being fed he encounters an officer of his unit, who, demonstrating the most friendly and equal relations, persuades Van to help him escape. But, being free, the officer restores the distance and demands submission. In the course of the escape, Van kills the officer and returns to the location of the Red Army, having seen a fundamentally different, humane attitude towards the captured enemy. During the lightning operation, units of the Soviet troops occupy several border settlements and, after the signing of the Khabarovsk Protocol, victoriously return to their places of permanent deployment. Chinese peasants and farm laborers, among them Van, escort them like brothers.