In 1944, in a Northern Italian village called Reanoto, the SS massacre the entire population for aiding the Italian resistance, under the command of the brutal Major Taussig. The only witnesses are a group of boys aged 7 to 14, led by Aldo, who survive the carnage and vow to exact revenge.
That same night, a detachment of US Army paratrooper saboteurs lands with a mission to destroy a strategic dam, hoping to clear the way for the Fifth Army's advance with the local partisans. Their drop zone is swiftly found by German forces commanded by Hauptmann von Hecht, who kill all the paratroopers except for their leader, Captain Turner, who lands unconscious and hidden among the branches of a tree. The Germans seize the captured demolition gear.
Aldo and his friends rescue Turner, hiding him from the Germans. Realizing he needs medical care, they abduct German doctor Bianca Freedling and keep her captive even after Turner recovers. To avenge the massacre, Aldo pushes Turner to train him and the boys in weaponry and tactics. Turner seizes the opportunity to complete his sabotage mission, using the boys as his new unit rather than his late command. He has them steal the gear from von Hecht’s headquarters, killing SS Rottenführer Gunther in the process, though Aldo hides the detonators for the day of their revenge. Turner also teaches them to operate German MP 40 guns.
Turner and the doctor travel to the dam, where the doctor attempts to stab Turner with scissors and then rushes toward a passing German armored car. Turner drags her into cover and, in a brutal moment, rapes her.
In response to Gunther’s death, Standartenführer Jannings pursues Turner and his “Dead End Kids,” while von Hecht is placed under Taussig’s command and regular Wehrmacht troops are reassigned to guard a tunnel. Not long after, Turner and the boys hijack a truck and mount a surprise assault on SS headquarters, slaughtering Taussig’s men. For most of the boys, killing the SS proves enough, but Aldo grows emotionally unstable and hungry for more killing.
Von Hecht, after a dispute, shoots Taussig and then goes after Turner and the boys alone. While Turner and several of the boys plant explosives on the dam, Aldo and a few others disobey orders and engage the German guards atop the dam, a move that nearly jeopardizes the mission. In a fierce moment, Aldo takes control of an MG 42 and becomes blood‑drunk, mowing down Germans and even firing on his own friend Carlo when Carlo blocks his shot. Despite von Hecht’s interference, Turner and the kids successfully plant the charges and blow the dam, flooding the valley.
With the dam destroyed and German forces routed, American troops begin to move in. Turner learns that Carlo has died and another boy died protecting Bianca and some younger children, prompting remorse over involving the children and causing him to lay down the guns. Aldo refuses to surrender his weapon and confronts von Hecht, who survives the dam attack. Turner arrives and cannot deter the boy from finishing off von Hecht, and he stops Aldo by taking the gun away and capturing von Hecht, who expresses a quiet admiration for Turner’s success.
Turner, Bianca, von Hecht, and the surviving boys except Aldo go down to meet the approaching American column. Aldo lingers behind. After ensuring the others are aboard a truck, Turner returns for him. The boy angrily throws rocks at Turner for intervening, but he is finally overwhelmed by remorse for Carlo’s death and asks for forgiveness. Turner grants it and carries the frightened, contrite boy to the waiting truck, signaling a fragile, hopeful end to a brutal ordeal.
