Russia, World War II, during the Nazi invasion. The date is never mentioned but judging from references to "the front around Tula" and comments about the Soviets finally striking back, the time seems to be fall 1941, near the end of the German advances that started with the invasion in June. The setting is an isolated bunker behind the German lines that is home to a little squad of guerrilla fighters. The leader is Vladimir (Peck), who was an architect before the war but now is a fearless warrior against the Nazis. Among the others in the bunker are Semyon, a professor; two orphans, 16-year-old Mitya and his little sister Olga; and Yelena, a former factory worker who has become a hardened guerilla warrior.
Into this mix comes Nina (Toumanova), a ballerina who blundered into one of the guerillas by accident when her theater troupe was ambushed and destroyed on the road by Nazis. The presence of a delicate stage dancer among this group of resistance fighters causes some disturbance, especially when Nina and Vladimir fall in love.
This film is one of a handful of pro-Soviet movies made in Hollywood during that narrow window 1941-45 when America and Russia were allies; see also The North Star and the much weirder Mission to Moscow. The film debut of both Peck and Toumanova. Toumanova, a Real Life ballerina, went back to ballet and only dabbled in acting thereafter. Gregory Peck soon became a huge star. Alan Reed, who played Sasha, is better known without the fake Russian accent as the voice of Fred Flintstone on the original The Flintstones.
- Bittersweet Ending: Everyone in the cast except for little Olga dies, most of them in the climactic battle. Their diversionary tactic draws some thirty German tanks, which leads to their annihilation, but also allows for the breakthrough of the main Russian attack, beginning the liberation of the motherland.
- Catapult Nightmare: Nina bolts up in bed from sleep at the exact moment that Yelena is killed by Germans in the forest.
- Dramatic Gun Cock: The German prisoner dramatically works the bolt of the rifle after grabbing it off the rack and pointing it at Nina.
- Face Death with Dignity: Mitya spits in the face of a German officer to stop him from finding Vladimir in the attic; he's executed for it. Just before he's hanged a defiant Mitya shouts "Death to the German invaders! Kill them, burn them, poison them!"
- Face Framed in Shadow: Vladimir is introduced this way, as he descends the steps and angrily starts barking about how he managed to make it inside without being challenged by a sentry.
- Father, I Want to Marry My Brother: As they chat about what life might hold after the war, Olga tells Sasha "in those days, I'll be married to Mitya." An amused Sasha explains that there are laws against marrying your brother (Olga looks to be about ten, which makes this moment pretty weird).
- Fish out of Water: Nina the delicate ballet dancer is initially very much out of place in a band of hardened guerilla fighters. Little Olga, who does the cooking and cleaning, is irritated that Nina doesn't know how to help.
- Friends with Benefits: Using some circuitous language, Vladimir strongly implies that he and Yelena have been fooling around, but it "was not love." Given her reaction to the arrival of Nina, Yelena seems to have felt differently.
- Interplay of Sex and Violence: Nina and Vladimir, who have had some sexual tension, wind up consummating their relationship in the forest immediately after they blow up a German train.
- Last Stand: Every single member of the squad that remains is killed defending their post against an attack by thirty Nazi tanks—but it was a Last Stand with a purpose, diverting the Germans while the Russian attack hits elsewhere.
- Love Triangle: A fairly one-sided one as Vladimir is obviously falling in love with Nina and does not seem to return Yelena's feelings for him.
- Narrator: Opens and closes with a narrator talking about the little band of guerrillas and how they are just one of many fighting behind the lines against the German occupiers.
- Plunger Detonator: Vladimir uses one to set off a dynamite charge that blows up a rail line and destroys a German train.
- La Résistance: Soviet guerrillas wreaking havoc behind German lines. In Real Life units like this did in fact cause huge problems for the Nazis.
- Spy Speak: "The snow will fall tomorrow" is the message Nina is told to deliver to Vladimir—it's the signal that the great offensive is about to begin.
- The Squadette: Until the arrival of Nina, who at least at first isn't a fighter at all, Yelena was the only woman in the band. But she's really good, boasting of 63 kills.
- Title Drop: The opening narration says the guerillas lived "days of imperishable glory."
- Took a Level in Badass: For Nina this moment comes when, having earlier flinched at the prospect of killing the German prisoner, she shoots him in the back several times as he climbs the stairs. By the end she's a capable front-line soldier.
- Translation Convention: The Russians speak in English and the Germans speak in German, to make the American audience identify with its allies.
- Video Credits: Not just video credits, but narrated video credits, with the narrator naming and describing the characters and in the case of Peck ("Vladimir as played by Gregory Peck, distinguished star of the New York stage") and Toumanova ("Nina as played by Tamara Toumanova, the internationally famous ballerina") even naming the actors.
- Vodka Drunkenski: The opening narration describes Sasha as "the amiable drunk." In the first scene Sasha arrives at the bunker in a state of intoxication, having liberated a flask of liquor from a German he killed.