atiana Metanova wakes up on 22 June 1941, the day before her 17th birthday, to her older sister Dasha coming home and declaring that she is in love. That same morning, Vyacheslav Molotov announces Germany has invaded the Soviet Union. Tatiana’s parents send her twin brother Pasha to a boys’ camp so that the army won’t draft him. Tatiana, who is young and naive, is excited by the war. While her family focuses on sending Pasha safely away, Tatiana is entrusted with buying food and supplies. Unable to find much to buy, she buys a scoop of ice-cream, causing her to miss her bus. While waiting for the next bus, she notices a red army officer watching her, and he eventually crosses the street and introduces himself as lieutenant Alexander Belov.
After an embarrassed introduction, Alexander and Tatiana become attracted to one another and he helps her buy food at the Officers’ store. Alexander’s irritating friend Dimitri insists on helping them carry the boxes home. When they arrive at Tatiana’s apartment, they discover he is the man Dasha has fallen in love with. Tatiana is disappointed but doesn’t want to come between him and her sister. However, Alexander visits her the following day, meeting her outside of the Kirov factory where she works. After a few weeks of walking her home, Alexander and Tatiana’s attraction is undeniable. Still, Tatiana begs Alexander to stay with Dasha and not break her sister’s heart. Alexander and Tatiana’s bond grows deeper as Alexander tells her he is an American who emigrated with his parents, now dead, in 1930. After a few weeks, Alexander, who is annoyed at Tatiana’s unwillingness to fight for him, breaks up with Dasha and stops visiting the Metanovs and Tatiana.
The Metanovs are heartbroken over Pasha, as they cannot get through to the camp and hear reports it has been under fire. Tatiana overhears her parents saying that they would have preferred to lose Tania and decides to volunteer at the front in order to find Pasha and bring him home. When she arrives at the Luga front, the boy’s camp is empty. Tatiana takes refuge in a building that is bombed and is seriously injured. Dasha asks Alexander to find her, and he takes Tatiana back to Leningrad, sharing their first kiss on the way.