On September 6, 1950, at the beginning of the Korean War, Lt. Benson and his platoon are stranded on a hillside, unable to contact division headquarters on their radio and unable to advance because their truck is beyond repair. After it is discovered that one of the men has been quietly bayoneted by a Korean sniper, Benson realizes that their one slim chance for survival is to embark on the arduous march to hill 465, where the division is located. A short time after they begin, Benson sees a speeding jeep on the horizon and determines to commandeer the vehicle. As the jeep barrels through the platoon, Sgt. Nate Lewis stops it, angering the driver, Montana, a sergeant who is accompanying his shell-shocked colonel. Brashly telling Benson “we’re licked,” Montana explains that the colonel, who cannot speak or walk, was too close to an exploding mine. Benson orders Montana to take the colonel out of the jeep, then tells his men to load their gear onto it. Montana draws a knife on Benson, but acquiesces and gently carries the colonel to the shade of a tree. The men then start off, walking alongside the slowly moving jeep. Sgt. Killian, the platoon mechanic, tells his young friend Cpl. Zwickley, who is feverish and afraid, that he can ride in the jeep. A short time later, radioman Sgt. Riordan is finally able to reach division, but just as he makes contact, a sniper shoots out the handset. When the sniper is shot out of the trees and no one from the platoon takes credit, Montana comes forward, admitting that he did it. Benson then draws out another sniper but when he holds his hands up in surrender, Montana goes against orders and kills him. Benson is enraged at what Montana has done until he sees that Montana correctly ascertained that the Korean had a pistol in his hat. Now realizing that he can use Montana’s experience, Benson agrees to let him come with the platoon, allowing the colonel to ride and Zwickley drive. When the group resumes their slow advance, Killian is assigned to the rear watch. Unaware that he is being observed, when Killian stops to rest and pick some flowers for his helmet, he is killed by a bayonet in his back. A short time later, when the men reach a stopping point, Benson orders Montana to relieve Killian. Realizing that something is wrong, Montana calls for Benson, who puts himself into the line of fire to retrieve Killian’s helmet. Hearing what has happened, an hysterical Zwickley calls out for Killian, but Benson stops him and gives him Killian’s flower-adorned helmet. As they travel on, Montana recognizes faint noises in the brush signaling more snipers. After he sits down and pretends to doze, two snipers sneak up from behind him, but Montana quickly opens fire, apparently killing both. As Benson chastises Montana again for impulsively killing an enemy soldier, one of the snipers grabs his communication device and quickly broadcasts a message before Montana kills him. Because Benson knows some Korean, he tells Montana that the sniper was reporting their position, and moments later, they are barraged by enemy shells. With only six miles to go to hill 465, Benson recognizes that they must leave their position. He orders his men to wait for a lull in the shelling pattern then quickly run past the danger zone in pairs of two, in alphabetical order. When Benson calls out Montana’s name, he refuses to leave the colonel, saying that his real name is Joseph R. Willomet. Most of the men make it through the shelling, and when only Montana, Zwickley, Benson and the colonel are left, they carefully move the jeep to safety. Advancing to within an hour of hill 465, as they slowly walk through a wooded area, Lewis finds a mine among the fallen leaves. Worried that his men will panic, Benson orders them to divide into two columns, one column to follow his footsteps and the other to follow Montana’s. Montana balks at the order, saying that he must take care of the colonel, but when the colonel tries to say something, Montana realizes that he wants him to follow Benson’s orders. Near the end of the minefield, a Korean soldier drops down from the trees and begins to fight Montana. Benson orders Montana not to shoot, and the Korean puts his hands up. He then gives Benson a UN flier and says, in Korean, that he is tired of fighting. Still suspicious, Benson orders him to lead them through the minefield. At the foot of hill 465, Benson then sends the Korean up the hill to see if anyone will fire. When a barrage of gunfire kills him, Benson assumes that the soldiers at the top are American. A moment later, three men in American uniforms appear at the top of the hill and call out “Hey, G.I.s.” Although some of Benson’s men are elated, Montana immediately opens fire and kills the three soldiers, who, when their bodies roll down the hill, are revealed to be Korean. After lashing out at Montana for always being right and for saying it is better to shoot first and ask questions later, Benson breaks down, yelling that they are all alone, that nothing exists beyond the hill. That evening, as they take refuge in a cave, Benson recovers his composure as the loyal Riordan and others sneak up the hillside to see the ridge. Benson then allows Montana to leave with the colonel, even though Montana thinks Benson is a fool to think that only twelve men can take the hill. As the men prepare to attack the hill, Benson tells Zwickley that he can stay in the cave, but Zwickley, now wearing Killian’s helmet, summons the courage to join the maneuver. Benson goes forward to draw enemy fire, while his men take position. From a distance, the colonel sees what is happening and, without Montana realizing it, starts to come to life. The colonel then rushes out of the jeep toward the action. Montana yells after him, but the colonel keeps going, even after he is temporary knocked down by the force of an exploding grenade. Using all of his strength, the colonel gets to the top of the ridge and kills two Korean gunners but is himself killed by a third. When his body rolls down the hill, Montana finds him and drags him to safety. As Montana lovingly tries to make the colonel comfortable, the colonel smiles and says “son,” then he hands Montana two Silver Stars from his pocket. Wracked with grief for the man who had been like a father to him, Montana opens fire on the enemy. A short time later, Montana and Benson appear to be the only Americans alive. Although Benson is despondent and bitterly says that Montana should kill him if he wants to keep killing, Montana suggests that the two of them could take the hill. Although he is sure it is hopeless, Benson agrees. As they exchange fire and grenades with the Koreans at the top of the hill, Benson and Montana are joined by Riordan, the only other G.I. still alive. Exhausted, they fall asleep and wait for certain death in the morning. However, when they awaken, they hear the sound of approaching American forces. Now Benson asks for the Silver Stars that the colonel had given Montana, medals that the colonel did not have time to hand out. As Benson reads the names of all of his men who have died, Montana tosses the medals over the hill in their memory. When Montana asks if he will say anything about the colonel, Benson replies, “I don’t think we have to say anything for him.”