According to the story of the same name by Aleksandr Avdeenko. The end of the 50s. Transcarpathia. Two saboteurs cross the border near Tissa. One dies during detention, and the second, under the guise of a front-line soldier Ivan Belograi, appears at the state farm and begins to look after Theresa, whom he met by correspondence. Frontier guard Andrei Smolyarchuk, in love with Theresa, is the first to suspect a spy and is trying to find out what his purpose is...