Prosperous New York City ad executive Bill Compton (Patrick) kills his daughter's drug dealer boyfriend Frank in a fit of rage after she overdoses and winds up in the hospital, then—after stealing his drugs—flees to a local bar to calm down. There, he overhears factory worker Joe Curran (Boyle), who hates hippies, blacks, and anyone who is "different", ranting and repeatedly saying "I'd love to kill one". Compton accidentally blurts out "I just did", faking a smile after realising he's made a public confession.
Days later, Joe reads about a drug dealer murdered blocks from the bar, and immediately realises Compton was the killer. He contacts Compton, and the two form an odd friendship, introducing each other to their respective friends and family.
During an awkward dinner with the men and their wives, Bill's daughter Melissa (Sarandon), having escaped from the hospital, comes home, overhears him confess to the murder and storms out of the apartment, asking her father, "What are you gonna do, kill me too?" He tries to stop her, but she breaks away.
Bill and Joe search Greenwich Village for Melissa. During their search, they meet a group of hippies at a bar. Joe and Compton tell the hippies they have drugs, and are invited to join them at a pot party. The hippies steal the rest of the drugs plus Joe and Compton's wallets.
When he discovers the theft, Joe beats one of the girls until she tells him that their boyfriends often spend time in a commune upstate. Joe and Compton drive to the commune, bringing along some rifles and ammunition, "just to scare them." When they see the hippie thieves and demand their wallets back, one of the thieves tosses their empty wallets and begins to run away. Joe shoots the thief and goes on a rampage, firing at everyone in the commune. Compton protests, but Joe ignores him, mowing down anyone in his path including people who had no involvement in the theft.
When more hippies arrives at the door and Joe is out of ammo, he encourages Compton to join in. Compton shoots and kills several of them, and a girl in the group flees out of the building. Compton runs to the doorway and fires at the fleeing girl's back, hitting her. As she falls, she is revealed to be Melissa. Compton cries out her name and he hears in his mind, once again, her voice asking, "What are you gonna do, kill me too?"
The character of Joe is a clear influence on the much less violent but similarly prejudiced Archie Bunker in All in the Family, which debuted only a couple of years after this movie. Peter Boyle was so appalled at the Misaimed Fandom directed at Joe—apparently much of 1970 America was OK with hippie-murdering—that he turned down several roles in films that glorified violence, including The French Connection.
Not to be confused with the 2013 film of the same name starring Nicolas Cage.
Joe provides examples of the following tropes:
- Asshole Victim: Frank is an obnoxious drug dealer who gets Melissa hooked on heroin. The hippies who steal Bill and Joe's wallets too, even if they suffer Disproportionate Retribution.
- The Big Rotten Apple: The seedy New York of Midnight Cowboy and Taxi Driver.
- Disproportionate Retribution: Three admittedly scumbag hippies steal Bill and Joe's wallets. Bill and Joe murder them, and their friends.
- Downer Ending: Does it get more than downbeat than Bill shooting his own daughter in the back?
- Drugs Are Bad: Hard not to draw that conclusion when a high-out-of-her-mind Melissa is getting arrested for causing a disturbance in a convenience store.
- Fan Disservice: The sexy orgy gets a lot less sexy immediately afterwards, when Joe discovers their wallets were stolen, and he starts beating and slapping the naked hippie girl he just had sex with.
- Approximately 15 seconds into Susan Sarandon's film career, she strips naked and hops in a bathtub, joining her hippie boyfriend.
- Then there's all the gorgeous naked hippie girls at the orgy that Bill and Joe join.
- Good People Have Good Sex: And bad people have bad sex. The more sympathetic Bill pronounces his sex with the hippie girl as "outrageous", and she is clearly satisfied. The girl who has sex with monstrous Joe, however, is unimpressed, saying "You just broke the land speed record."
- Gray-and-Grey Morality: Neither the hippies nor the protagonists are overly sympathetic; the hippies (except Melissa) are largely criminals and junkies without many redeeming features, Bill and Joe are uptight, out-of-touch and ultimately murderous.
- In the Back: How Joe and Bill kill several hippies.
- Ironic Echo: Melissa's "Are you going to kill me too?" insult gets played back at the end, when Bill actually does kill her.
- Odd Friendship: Joe the working-class stiff and Bill the white-collar executive. Although Bill admits to his wife that at least part of the reason he's hanging out with Joe is to keep Joe happy, as Joe knows he's a murderer.
- A Party, Also Known as an Orgy: Bill and Joe, looking for Melissa in Greenwich Village, run into some hippies who lure them to the hippies' apartment. After sampling from Bill's large stash of drugs (taken from Melissa's boyfriend), the hippies lose their clothes and the orgy follows.Joe: All my life I've never been to an orgy. This is an orgy, isn't it?
- Politically Incorrect Hero: Joe's introduced telling a friend that "forty-two percent of liberals" are gay while praising George Wallace. He only gets more loveable from there.
- Villain Protagonist: Joe is a horrible monster, a racist, a sexist, a homophobe, a hater of young people, angry and violent. He clearly enjoys it at the end when he slaughters a house full of hippies.
- Worst News Judgment Ever: "HIPPIE DEAD THREE DAYS" probably didn't deserve to be a front-page above-the-fold headline in a New York City paper.
- Would Hit a Girl: Joe beats the hippie girl he just had sex with after he discovers the other hippies stole his and Bill's wallets.