Penelope Ryan has been raising her son, twelve-year-old Paul, alone for eight years since her husband Harold, a world-famous sportsman, disappeared while searching for diamonds in the Amazon jungle. Despite believing her husband is probably dead, Penelope has not changed their safari-themed Manhattan apartment, keeping Harold's large collection of taxidermy hunting trophies and his lion roar and hyena cackle doorbells. One night, Penelope's pacifist suitor and neighbor, Dr. Norbert Woodley, suggests that they remove the "carnage" from the walls, while Penelope's other suitor, vacuum salesman Herb Shuttle, who idolizes Harold for his heroism, arrives to take Penelope to a boxing match. Woodley lambastes Herb for watching violence for sport and Penelope for wearing a jaguar fur coat. Meanwhile, Paul, who worships his war-loving father, protests that no one is celebrating Harold's birthday that night and runs from the apartment. Herb attempts to find Paul, but when he loses him in the park, returns to the apartment with a discount birthday cake which reads "Happy Birthday Wanda June," hoping to celebrate his hero with Paul. After Penelope and Herb leave for the fight, Woodley answers the Ryans' door to two men, who identify themselves as family friends; actually, they are Harold and Col. Looseleaf Harper, with whom Harold was lost in the jungle. Woodley announces that he is Penelope's fiancé and ushers them out, but Harold and Looseleaf reenter after Woodley leaves. Having lost contact with civilization, the two men are awed by the use of profanity and the change in sexual attitudes. Weary of Looseleaf's constant chatter, Harold brusquely suggests he return home and looks curiously at the birthday cake for "Wanda June." Meanwhile, in heaven, little girl Wanda June explains that she was killed by a passing ice cream truck on her birthday and now resides in heaven, where the dead happily play shuffleboard together. Back at the apartment, Paul returns home to find Harold, who claims to be his father's friend. Paul tells him that he despises Woodley and that Penelope attended college during Harold's disappearance. Harold laments that education will have ruined Penelope's charm and then claims that "Harold" has bravely killed a despicable villain, Major von Konigswald, during World War II. In heaven, von Konigswald plays with children and relishes the deplorable acts he committed, claiming that he killed 100 times more men than the boastful Harold. Back on earth, Penelope, unaware of Harold's return, comes home and announces to a dejected Paul that she is marrying Woodley. Suddenly, Harold enters the room, but a shocked Penelope does not respond to his amorous embrace and instead locks herself in the bedroom. Afterward, while walking with Paul, Harold explains that after several unsuccessful marriages, he met Penelope when she was an eighteen-year-old diner carhop. Meanwhile, Looseleaf, who has gone to a neighborhood bar, is recognized as the man who dropped the bomb on Nagasaki. When a hippie questions the morality of the act, Looseleaf tries to explain that he was only following orders and then quickly departs. At his old home, Looseleaf's mother-in-law dies from shock upon seeing him at the door and his wife Alice, who has since remarried, orders him to leave. The next morning, Penelope asks Woodley to help cure Harold of a cold he has developed and begs the two men to become friends. Ignoring Penelope's request, Harold uses a jungle root for a cure and viciously mocks Woodley's profession as a medical doctor for stealing cures from natives. Soon after, Harold tries again to woo his wife, but she remains unreceptive to his advances. Yelling at Penelope to make breakfast for him and Looseleaf, who has returned to Harold's side, Harold then calls her his "nigger," prompting Penelope to equate his type of heroism with that of abusive men who hate their homes and rape women as if they are their prisoners, a theory she has learned from Woodley. Furious, Harold breaks into Woodley's apartment and destroys his most prized possession, an irreplaceable violin, prompting Penelope to leave Harold for good. Back in heaven, Harold's ex-wife Mildred tells Wanda June and von Konigswald that she despises premature ejaculators like Harold, who take out their frustration by going to war. Later at the apartment, Herb, who has quit his job to be Harold's attendant, eagerly acquiesces to Harold's every command. Meanwhile, Harold berates Looseleaf for allowing his wife Alice to force him to quit being a test pilot, but Looseleaf defends Alice's concern about his profession, describing in detail the excruciating horror of being in a plane that could explode at any second. When Penelope arrives to pack her things, Looseleaf announces that he understands why she is leaving Harold. Unable to take any questioning of his authority, Harold further alienates himself from Looseleaf, stating that the bombing of Nagasaki was Looseleaf's only brave moment. On his way out, Looseleaf quietly retorts that he would have been brave if he had had the courage not to follow orders. Harold then insults Herb, orders him out and yells that the country has been lulled into pacifism by brainwashing, like the "blue soup" that the Amazonian natives used to control him and Looseleaf for so many years. Harold then splits a table with a sword, prompting Paul to point a rifle at his father to protect his mother. Penelope understands that Harold is trying to force Paul to shoot him, a convenient ending to his hero's life. When Woodley arrives in the midst of the standoff, Penelope takes the rifle to protect her son and fiancé, but then has to have Paul show her how to load it. Suddenly, Harold grabs the gun, forces a groveling apology out of Woodley and insists that they fight with knives. Woodley refuses and walks out, but not before telling Harold smugly that the root he used was originally found by a Harvard botanist, not a jungle native. Pointing to all the dozens of taxidermy beasts lining the walls, Penelope yells that there is no honor in being dead and laments that Harold has stripped the life from so many animals. Paul follows by calling Harold a "clown." Realizing that his way of thinking is now obsolete, Harold hands the gun to his son to "finish the job," but Paul cannot shoot his father. Harold then takes the gun and leaves the room. Hearing a shot, Penelope believes Harold has ended his life, but he returns unharmed and asks his family to leave. On the way out, Paul warns his father that he will soon have no friends left.