The story starts with a plot device out of Gabriel Over the White House: a mediocre man acquires strange, divine powers after surviving a car wreck. Ted Mathews (Jonathan Kidd) is celebrating his graduation from a night-school course in business administration by joyriding with his impatient girlfriend Terry (Lyn Statten) when they collide with another car and go over an embankment. Barely hurt, Ted checks on the other car after verifying that Terry's still alive. He sees an unconscious, bleeding driver and, convinced that he's killed the man, seems to suffer traumatic amnesia, heralded by watery dissolves. He barely acknowledges the still-unconscious Terry before wandering from the accident scene.
Ted's wandering takes him to the trailer of an itinerant preacher with a Noah's Ark on wheels. This modern Noah takes Ted and sets him up as a faith healer. Now called Tad Morgan, he has talent for his work. We see him give hearing to the deaf and life to the limbs of a lame boy as a devout crowd watches slackjawed, arms prayerfully and creepily crossed over their chests. Tad's power keeps the cash flowing in, which he hopes to convert into a children's hospitals.
Soon, however, Terry reappears. She's been on a downward spiral since taking the rap for the car wreck. She keeps house with Pete (John Harmon), a wretch who rolls rummies to keep the couple in booze. She approaches Tad for some money, but when she realizes that Tad, barely remembering the accident, still believes that he killed the other driver, who only suffered a concussion, she also realizes that Tad is ripe for long-term blackmail. When she gets impatient with occasional checks -- the booze seems to run out faster and faster -- she decides to marry Tad, to Pete's jealous dismay. But first she has to get Tad seriously, profoundly liquored up. This lubricated courtship climaxes in a travesty of a marriage, Terry propping up a barely conscious Tad while a skeevy JP performs the ceremony, then dumping him to the floor the moment the man pronounces them husband and wife. Through it all, her strange if not inexplicable attraction to Pete persists. Codependence is a hell of a drug.
Having touched bottom, Tad struggles to free himself. Drastic action is necessary. The moment comes on a dark stretch of bridge as a weary Terry sits on the stone ledge and demands a foot rub. Tad complies but starts pressing too hard, until he heaves her over the side and into the drink. He runs repentant back to church, but as if she, too, had been transfigured by that original accident, Terry seems unkillable. Like a raunch Rasputin, or like a wet rat, she rises from the waters and returns home, where Pete has made himself at home, put on Tad's robe, and passed out drunk in the marriage bed. Seeing only the robe, and probably seeing red, Terri gets a gun out of a drawer and fires four shots into her true love.
Realizing her mistake, Terry stalks Tad at the church and through a cemetery as the film nears its dark epiphany. Confronting him at last, Terry fires her last two shots, but praise God! Tad's Bible absorbs the bullets. As if possessed, Tad begins reciting the Lord's Prayer as he puts his hands over Terry's throat and chokes the evil life out of her once and for all. He had been given the power to heal, but maybe his mission on Earth was to kill, after all. For now that his work is done, the heart attack hinted at earlier strikes him on the church steps, and his soul departs his body for parts unknown.
The synopsis speaks for itself: The Seventh Commandment suffers from a spiritual confusion that could only come from deep if not uncritical faith. It's all too straightfaced and guileless, if not artless, to be written off as cynical exploitation. It's like a tale told by a raving, repentant drunk, while he's still drunk. Naively depraved, its exploitative moralism is laughably appalling. You may be content to laugh, but you should be appalled. You may be appalled, but you ought to be laughing, too. This film is a genuine nightmare, but for someone to have this nightmare is sort of laughable. What I'm saying is that if you have a taste for something other than good taste, if you're morbidly fascinated by the sometimes feverish sincerity of bad cinema or just like to laugh at it, The Seventh Commandment comes highly recommended.