The film begins with Henry Spencer (Jack Nance) floating aimlessly in space, with a surreal depiction of his brain represented by a rocky planet visible through his head. This rocky landscape houses a peculiar structure featuring a significant hole in its roof. Within this haunting building, the Man in the Planet (Jack Fisk) diligently operates levers that symbolize Henry's central nervous system. This unusual opening sequence serves as a metaphor for Henry's intimate encounter with Mary X (Charlotte Stewart), culminating in a bizarre imagery of a spermatozoon emerging and diving into a watery abyss, indicative of Mary's anatomy. Time lapses and from the depths of darkness, a creature emerges.
Next, we see Henry as he walks through a desolate industrial landscape, carrying a small brown paper bag, his journey marked by eerie carnival music contrasting the silent, machinery-laden environment. Conveying a sense of isolation, there is a prominent lack of life around him, accompanied by the distant sounds of whistles and ship horns cutting through the heavy machinery's roars. Upon arrival at his dilapidated apartment lobby, he checks his mailbox, finding it empty. Ascending to Room 26, he encounters the Beautiful Girl Across the Hall (Judith Roberts), living in Room 27, who informs him that Mary has invited him for dinner.
Inside his dimly lit apartment, Henry sets down his groceries, flicks on some light jazz from his record player, and momentarily engages with the hissing radiator, a symbol reflecting his dark thoughts, and glances longingly at a bleak view of a wall through his only window—the claustrophobic confines echoing the oppressive weight of his solitary existence. The atmosphere suggests a post-apocalyptic scenario, especially emphasized by an ominous mushroom cloud imagery. After a superstitious act involving a stone thrown into water, Henry examines a torn picture of Mary, hinting at underlying troubles.
That evening, under the cover of darkness, Henry traverses through the grim landscape to dine with Mary's family. This encounter reveals the strained dynamics between Henry and Mary, complicated by the revelations of their past. During dinner at the X household, which features an uncomfortable interaction with Mrs. X (Jeanne Bates) and Mary’s father (Allen Joseph), we observe Henry's awkwardness in this tense environment marked by artificial food that horrifies him. Following dinner, questions about their sexual history culminate in an ultimatum that compels them to marry immediately.
After their wedding, the couple brings home a deformed baby, the product of their union, that intensifies Henry's existential dread. The sinister nature of their home life deepens when he discovers a small worm hidden in a sleek black box, prompting his thoughts of despair to resurface. As nights pass, the couple faces the torment of a continuously crying baby while they are surrounded by the cacophony of a storm, factories, and trains, leading to Mary’s decision to leave Henry to handle their child alone, deepening his isolation.
The plot thickens as the Beautiful Girl Across the Hall returns home after a night that implies her own struggles, providing an unsettling parallel to Henry's crumbling reality. As days progress, the baby's health deteriorates, casting a grim shadow over Henry, who eventually succumbs to temptation with the Beautiful Girl, leading to a scandalous encounter.
The narrative takes a surreal turn when the lady in the radiator ([Laurel Near]) performs on stage, exuding an eerie calm as she sings, “In Heaven, everything is fine.” Amidst the chaos, Henry finds himself in a nightmarish vision involving his severed head, which is cruelly repurposed at an eraser factory. This grotesque transformation underscores the bizarre essence of his existence.
Upon waking, Henry's dark journey continues as he grapples with his monstrous reality, ultimately culminating in a shocking act against the baby, followed by fleeting visions of electrical chaos and the baby’s grotesque form. In the final scenes, the man in the planet pulls a lever, facing a shocking end, while Henry finds solace in what appears to be a transcendent afterlife, resolved to embrace the lady in the radiator amidst the surreal backdrop of his tragic existence.
In an alternative interpretation, the film alludes to a devastated America post-atomic war, surviving in a state of regression where technology has stagnated, and the population has diminished drastically. The societal implications suggest deep-rooted mental illnesses among the remaining inhabitants, heightened by the horrors of radiation. Henry's interactions and experiences encapsulate the struggles of a traumatized individual grappling with personal demons, ultimately leading to his tragic demise in a world riddled with despair and hallucination.
