The plot of the film takes place in Staten Island, and follows an unemployed Vietnam veteran living in total poverty with his nagging wife, his deformed baby due to Ricky having been exposed to Agent Orange that the US was spraying as a defoliant over Vietnam, and junkie friends. Unable to get a job and surrounded by the depravity of urban life and crime, he begins to lose his grip on sanity. The film received mixed reviews when it was released. Film Threat's Christopher Curry praised the film for its gritty realism, and Troma president Lloyd Kaufman calls it one of the company's true "masterpieces"; however, shockcinemamagazine.com called it "one of the ugliest, nastiest, most depressing movies of the decade" (though the review itself was a positive one), and Videohound described the film as "relentlessly bleak... you won't find a more depressing film outside an art-house cinema".
The film begins with stock footage scenes of warfare in Vietnam. An American soldier named Frankie is seen running alone through the jungle as his voice narrates. He explains that he "goes back there every night" right before he wakes up in bed with his wife in their squalid NYC apartment. The distorted cries of his baby are heard, and his pregnant wife wakes up to tend to the boy. They argue over Frankie's unemployment and their son's health. The baby is a mutant, portrayed by a puppet. Frankie assumes it was a result of chemical weapons used during the war.
The bulk of the film consists of long sequences of urban blight underscored by Ricky Giovinazzo's synthesizer soundtrack. A junkie scores from the local kingpin, Paco. Frankie waits in line outside the unemployment office. The junkie desperately searches for a needle to shoot up with. Frankie kills time entertaining a child prostitute. The junkie resorts to dumping the drugs directly onto a wound he opens in his arm and passes out. A random woman comes upon him and steals his gun and ammunition, putting them in her purse.
There is no work for Frankie at the unemployment office. Unexplained arbitrary things happen, such as one social worker asking another if he's seen his Veg-O-Matic. Frankie's social worker spaces out during their meeting and says, "Life is hot, and because life is hot, I must take off my jacket." He then resumes the meeting, imploring Frankie to go back to school because he has no marketable skills. Frankie is desperate for work, having been unemployed for four months.
He calls his father to ask for money. His father thinks the call is a prank, because he believes his son died in Saigon. Frankie explains that he was reported killed 15 years ago but he made it out alive and spent three years in an army hospital recuperating. He tells his father that his wife is pregnant again and they are being evicted, but his father claims that he is also broke and about to die from a heart condition.
Seemingly broken, Frankie comes across the woman who stole the junkie's gun and steals her purse, an out of character criminal act for him. She screams for help. Paco and his thugs chase Frankie. When they overcome him, they mercilessly beat him. The gun falls out of the bag during the pummeling. When Paco goes through the bag, he finds the bullets and realizes there must have been a gun in it. He turns around to see Frankie standing with the gun.
Frankie shoots all three men in a daze. He has been beaten to a pulp, and his voice over explains that his father was right: he had died in Saigon. He explains that his company had come upon a village where everyone had killed themselves to avoid being raped and murdered by the US soldiers. He realizes that he must similarly 'save' his family, and he returns home.
His wife is horrified by his appearance and briefly tends to his wounds. He is catatonic and hallucinates in front of the TV. Eventually, he reloads the gun and prepares to kill himself, but another hallucination reminds him of his purpose for returning home. Frankie walks into the bedroom, tells his wife that he loves her, and then shoots her in the stomach. As she lies on the ground, he shoots her three more times, yelling at her to die. He shoots the baby once and then picks it up from the crib. He cradles it and walks into the kitchen with it.
Frankie lays the baby in the oven, and turns it all the way to the cleaning setting. He then pours himself a glass of spoiled milk and drinks it, before committing suicide via gun. The final shot shows a train passing by into the night.
The movie is set in and was largely filmed in the Port Richmond section of Staten Island, where the main character dwells in apocalyptic squalor. It is Port Richmond's gritty streetscapes that assist in getting Giovinazzo's desired point across. The film has often been hailed for its raw depiction of inner city life, the struggles of poverty and the plight of veterans returning home from war.
The movie was shot on a modest budget causing the battlefield scenes to be shot in marshland across from the Staten Island Mall.
The initial theatrical release was met with severe skepticism. Writing for The New York Times, Vincent Canby dismissed the film as a 'family affair', which "means to be shocking but it more often prompts giggles. You don't often see movies as passionately, sincerely misguided as this." Reviewing the DVD release of the film in the same paper, Dave Kehr was more affectionate, admiring the film's gritty honesty, but admitting, "The entire world of Combat Shock seems to have aged beyond its sell-by date, an olfactory metaphor that Mr. Giovinazzo drives home with an unforgettable image involving a carton of spoiled milk."
The Tromasterpiece Collection, set on re-releasing Troma's finest movies, have released a 2-disc uncut version of Combat Shock, also featuring the original workprint of the film entitled American Nightmares, on July 28, 2009.