In June 1941, in the small Russian farming village of North Star, pig farmer Karp briefly visits the home of Dr. Kurin, his cousin Anna and her children Clavdia and Grisha. Later, Karp chats with teenager Damian, who is enthusiastic about the next day's planned walking trip into the city of Kiev with Clavdia, Grisha, Damian's girl friend Marina and his older brother Kolya, an air pilot on leave. At Marina's home, her little sister Olga and parents, Rodion and Sophia, discuss that evening's plans for the village feast. Meanwhile, at Damian's home, his parents, Boris and Nadya, and Kolya are disturbed to hear news over the radio of German troop movements within Poland and the recent bombing of London. That evening the entire village takes part in unloading the supply train and celebrates the season in song and dance. The next morning the young people set out in high spirits on their hike to Kiev and soon meet up with Karp, who offers them a ride on his cart. They join a long line of carts headed for the city, but soon Karp and Kolya hear a distinctive sound, and when Kolya realizes it is the buzz of aircraft, he stops the caravan and tries to get everyone into the ditch as bombs rain down on them. After the planes pass over, the hikers discover several people have been killed and their own cart destroyed. In North Star, the villagers are going about their daily routine when the dive bombers abruptly attack, and Sophia watches with horror as Olga is caught in the strafing gunfire. As the planes depart, the village radio announces that the Germans have invaded Russia and the two countries are now officially at war. Boris, the village leader, gathers the survivors together and declares that the men must depart for the hills to take up guerrilla activities and the women and older people must remain behind to burn the village before the German army arrives. Rodion gives the village the oath of guerrillas before the men ride away. Boris then goes to the nearest army post to retrieve munitions for the guerrillas, but on his return he is strafed by another wave of planes. His truck turns over near where Damian, Kolya and the others are regrouping. Before dying, Boris instructs his sons to deliver the munitions to the guerrillas or North Star will be lost. After burying his father, Kolya helps load the gun supply onto two wagons, then departs to rejoin his air group. A village scout on horseback sees the advancing German army and reports to the women, who begin burning their houses. The Germans soon arrive in North Star and shoot several villagers to stop the burning, then question the survivors about Rodion's whereabouts. When none of the villagers respond, the soldiers torture Sophia, prompting Kurin to protest to the medical officer, Colonel von Harden, who explains that there are many unpleasant Nazi policies that must be acted upon. Meanwhile, as night falls, the hikers rest by the roadside, and as German scouts drive by, Grisha's dog darts out barking and three soldiers are dispatched to investigate. Damian and Karp send the others to harness the horses while they ambush the German soldiers and set off again. Early the next morning an exhausted Kolya is on his fourth bombing run with a novice pilot, who decides to strafe a German armoured division, but the plane is shot up and the pilot and co-pilot killed, forcing Kolya to take over. Realizing the plane is too damaged to land, Kolya crashes it into the tank line. Meanwhile, in North Star, the Germans have converted one remaining building into a hospital, where they force the village children to make blood transfusions for their wounded soldiers. Kurin, watching von Harden's cold efficiency, is bitterly shocked and attempts to save a young boy, who later dies in his arms. He takes the child's body to his father in the guerrilla hideout. Out in the forest, the hikers realize that the only route into North Star is across the road and they must cause a diversion to halt the German transport. Damian volunteers and, unknown to him, Clavdia follows, determined to overcome her fear. Both successfully bring the transport to a halt, allowing the carts to dash across further up the road, but when the Germans fire on the fleeing youths, Clavdia is mortally wounded. Damian is stunned by an exploding grenade and when he comes to, discovers he has been blinded. When Damian and Clavdia fail to return to the carts, Marina insists on looking for them, and she and Karp soon find the distraught Damian. Incensed by the murder of the village children who died as a result of the blood transfusions, the guerrillas decide they can no longer wait for the munitions and must attack. Rodion and a handful of guerrillas slip into North Star undetected and into a warehouse that stores barrels of gasoline, which they silently pour into the river and then ignite with grenades. As the guerrillas storm the town on horseback, armed only with clubs, the weary hikers reach the edge of town with the guncarts. A sentry rushes them into town, where the guerrillas immediately arm themselves and continue their attack. At the hospital Kurin berates von Harden for claiming to despise those he nevertheless serves, then kills him. Later, after driving the Germans out, the surviving villagers leave the smoking remains of North Star, vowing to make this the last war and to fight for a free world.