Apocalypse Now takes place in 1969, during the heart of the Vietnam War. U.S. Army Captain and military assassin Benjamin L. Willard, played by Martin Sheen, awaits his next assignment in a cheap Saigon hotel. Willard drinks heavily and ponders his inability to adjust to the normal life stateside with his wife, and how he has found his place in the war torn country. The next day, Willard is summoned to a meeting with three military intelligence officers, who have a special assignment for his particular skill set.
One which requires a person with no qualms about killing. Even murdering a fellow U.S. serviceman. The three men assess that Willard is their man and dispatch him with a mission to follow the Nung River into the jungles of Cambodia to find a rogue Special Forces Colonel Walter E. Kurtz who has allegedly gone insane and is now commanding is own troops who treat Kurtz as if he is a god. The intelligence officers order Willard to infiltrate Kurtz’s team and to kill Kurtz.
Willard accepts the mission, but does so with ambivalence. Upon reviewing Kurtz’s bio, Willard begins to see the out of control Colonel as a kindred spirit. Willard joins a river patrol boat commanded by “Chief” and crewed by three other men, surfer Lance, “Chef”, and “Mr. Clean”. Their mission is take Willard upriver, but they are not made aware of Willard’s ultimate mission. As they travel towards the river, Willard sifts through the files on Kurtz, learning that he was a model officer – a possible future General, and begins to question his mission.
To get to the river, Willard and the PBR crew seek the assistance of Lieutenant Colonel Bill Kilgore, played by Robert Duvall. Kilgore commands an attack helicopter squadron that Willard needs to take out the Viet Cong stronghold at the mouth of the river so the PBR can begin its journey. Kilgore initially is uninterested in helping them, but soon recognizes Lance, who was a famous surfer before the war. Kilgore sees himself as a surfer and agrees to escort Willard’s group through the Viet Cong-held coastal mouth of the river due to the surfing conditions there.
The next morning, the helicopter raid commences, and Kilgore’s troops make short work of the Viet Cong in the village, but continue to draw fire from the enemy troops in the jungle. Kilgore calls in a napalm sortie while his troops try to surf the beach, and laments the potential end of the war some day. With the mouth of the river now in U.S. control, Willard and the PBR crew begin their journey into the heart of darkness.
During the river boat cruise upriver, Willard and the PBR crew take a journey back in time and leave the modern world behind as they travel up the river. Willard and Chef fight with nature when they encounter a tiger in the jungle when they get off the boat to get some mangoes. Establishing the first rule of the trip, never get off the boat. The crew encounter a group of servicemen at a USO/Playboy event where the soldiers resort to their most primitive nature and rush the stage in an attempt to get the Playboy Bunnies.
They run into, and ultimately slaughter, a Vietnamese family on a primitive fishing boat. The slaughter of the fishermen puts Chief and Willard at odds with each other as to who is really in charge. Mr. Clean Is killed by tracer fire from the Viet Cong, and Chief meets his fate at the point end of a jungle spear. All the while, Willard continues to read Kurtz’s file, learning that although effective, Kurtz’s command decisions became increasingly erratic the longer his tenure in country. Willard begins to question whether Kurtz is crazy after all or whether the military wants him dead because they can no longer control him.
After Chief’s death, Lance withdraws into a drug filled haze, but Chef, after being informed about Willard’s mission, reluctantly agrees to continue up river to drop off Willard. Along the way, the trio find burning villages and the riverbanks now ritualistically decorated with mutilated Viet Cong bodies.
Eventually the PBR arrives at Kurtz’s outpost and Willard and the two sailors are met by an American freelance photographer, played by very likely drugged up Dennis Hopper. Hopper raves manically that Kurtz’s is a genius and that he has a plan for Willard. Willard orders Chef to order an airstrike on the area, after seeing the numbers of Kurtz’s forces. Shortly after, Willard is captured and tied up by Kurtz’s men, and Kurtz, played by Marlon Brando, kills Chef by beheading him.
After being captured, Willard is brought before Kurtz who dismisses him as a mere errand boy for the military. But inexplicably, Kurtz does not have Willard killed, but instead, releases Willard to walk around the compound. Kurtz begins a dialogue with Willard, lecturing him about his theories on war, humanity, and civilization while praising the ruthlessness and dedication of the Viet Cong.
Although Willard acknowledges that Kurtz is insane, his interactions with the crazed Colonel allow Willard some insight into how the hypocrisy of conducting a “moral” war drove this person, a pure warrior and a moral man, into madness. Kurtz discusses his family and asks that Willard tell his son the truth about him in the event of his death, foreshadowing that Kurtz knows and accepts that Willard will ultimately kill him. Because of Willard’s personal admiration of Kurtz these words only stiffen Willard’s resolve to help the Colonel achieve some dignity.
That night, Willard stealthily enters Kurtz’s chamber as Kurtz is making a tape recording, and attacks him with a machete, a very primitive weapon. Lying mortally wounded on the ground, Kurtz, with his dying breath, whispers “…The horror … the horror …” Kurtz’s followers become aware of the commotion in the temple, and when Willard exits with a bloody machete, they bow down, willing to except Willard as their new leader. Willard, unwilling to except the role, grabs some of Kurtz’s writing and Lance and gets back onto the PBR. The two of them ride away as Kurtz’s final words echo eerily as the world fades to black.