In 1968, while waiting for his next assignment during the Vietnam War, Army Captain Benjamin Willard gets drunk and wrecks his hotel room in Saigon, South Vietnam. Because of his experience with reconnaissance operations, Willard is soon escorted to COMSEC Intelligence and briefed on a priority, classified mission to terminate the command of Special Forces Colonel Walter E. Kurtz, a decorated and brilliant officer who has apparently gone insane and is wanted for the murder of South Vietnamese intelligence agents. The General and Colonel at COMSEC relay that Kurtz has deserted the military and crossed into Cambodia with his own army of Montagnard Indians who regard him as a god-like figure. Although privately ambivalent about assassinating a fellow American officer, Willard accepts the mission and boards a Navy patrol boat (PBR), commanded by Chief, that will ferry him up the Nung River towards Kurtz’s outpost in Cambodia. Chief’s three young crew members consist of a saucier from New Orleans, LA known as Chef; champion surfer Lance Johnson from Southern California; and Clean, a teenager from the Bronx, NY. Needing an escort into the mouth of the Nung, the PBR seeks the transport assistance of the First of the Ninth, an Air Cavalry division of fighter helicopters led by Lt Colonel Kilgore. When Willard and the crew reach the Air Cavalry, the division is busy finishing up a raid on a coastal village, but Kilgore, an avid surfing fan, stops immediately upon learning that the famous Lance Johnson is present. Motivated by the surfing possibilities, Kilgore plans to transfer the PBR and its crew to an access point near the river that promises great breaking waves, but also heavy enemy artillery. The next morning at dawn, the PBR is lifted out of the water, and Willard and the crew climb aboard Kilgore’s helicopter for the ride to the mouth of the Nung. As the squadron assumes attack formation, their speakers blare Richard Wagner’s opera music, Ride of the Valkyries. Landing on the beach amidst enemy mortar fire, Kilgore orders his men to “surf or fight,” and, as warplanes bomb the nearby jungle, he remarks, “I love the smell of napalm in the morning.” With their boat back on the water, Willard and the crew continue their journey toward Cambodia. Farther upriver, while the PBR is refueled at a supply station, the crew stays to watch a raucous U.S.O. show featuring Playboy playmates. When the boat trip resumes, Willard keeps to himself, avoiding the antics of the crew, who are often under the influence of drugs, and studies Kurtz’s impressive dossier. While tracing Kurtz’s deviation from the U.S. military, he also begins to admire the Colonel’s nerve to become a Green Beret at the ripe age of thirty-eight and his execution of unauthorized operations. Willard reads letters that Kurtz wrote to his son describing the “unjustified” murder charges against him. Along the way, Chief decides to search a Vietnamese fishing boat for illegal trafficking of military supplies. In the confusion, a jittery Clean guns down the civilians on board, and Willard shoots a wounded woman dead, so as not to delay the mission. At the Do Luoug Bridge, the last Army outpost along the river, Willard is unable to locate a commanding officer in the mayhem of nighttime gunfire, but retrieves a mail shipment for the crew as well as ammunition before continuing upriver into Cambodia. The next morning while the crew is reading letters from home, the boat is attacked by artillery fire from the jungle, and Clean is shot dead. Later, they encounter a harmless barrage of toy arrows, but the crew is tense and begins firing into the trees. Suddenly, a spear pierces Chief and kills him. While Lance buries Chief, Willard reveals to Chef the actual purpose of his visit, to kill a deranged Green Beret colonel. Although angry about the absurdity of the mission, Chef agrees to accompany Willard to his destination. As the river leads them to the entrance of Kurtz’s compound, the PBR navigates slowly through a grouping of Montagnard Indians in canoes and cautiously approaches the bank where dead bodies, severed heads and pagan idols are displayed. A fanatical American photojournalist, who is a devotee of Kurtz, greets them on the riverbank and cautions them that the Indians are very protective of Kurtz. Chef stays with the boat while Willard and Lance look around the area and track down the Colonel's location. Before leaving to meet him, Willard instructs Chef to radio for an air strike if he is not back by a certain hour. The Indians handcuff Willard and lead him inside a temple. In a darkened lair surrounded by armed bodyguards, the philosophical Kurtz interrogates Willard and acknowledges the assassination orders by ridiculing Willard as an “errand boy sent by grocery clerks.” While Willard is held captive in a bamboo cage, the photojournalist tries to convince him that the “genius” Kurtz has plans for Willard, otherwise he would not be alive. With no sign of Willard, Chef radios for the air strike, but soon afterwards, Chef is decapitated, and Kurtz drops the severed head into Willard’s lap. Eventually, Willard is carried back to the temple and offered food, water and his freedom. Over several days, Willard remains inside the temple close to Kurtz and listens as the Colonel reminisces and lectures on topics such as horror and judgment. In case he is killed, Kurtz wants his son to know the truth of what happened and asks Willard to tell him. Willard senses that Kurtz is ready to die and decides to complete his mission. One night, as the Indians engage in a ritual slaughtering of a water buffalo, Willard covers his face in war paint and attacks Kurtz with a machete. Dying, Kurtz whispers his final words, “the horror, the horror.” As Willard descends the stairs of the temple, he throws down the machete and in turn, the crowd of Indians lay down their weapons as he passes by them. Grabbing Lance’s hand, Willard leads him back to the boat, and the two soldiers pull away from the compound.