In the sun-soaked suburbs of Southern California during the pivotal year of 1984, a seemingly average and curious sixteen-year-old high school student named Todd Bowden stumbles upon a shocking secret about his reclusive and elderly neighbor, Arthur Denker. As it turns out, this old man is actually Kurt Dussander, a former Nazi Obersturmbannführer who has evaded justice and is now a fugitive war criminal. Driven by a dark fascination for the heinous activities of the Nazis during World War II, Todd resorts to blackmail when he threatens to expose Dussander’s true identity, compelling the old man to share harrowing tales of the death camps.
As their strange relationship deepens, Todd's life begins to unravel. His once-promising grades plummet, and his interest in his girlfriend, Heather McComb, dissipates entirely as he becomes further ensnared in Dussander's malignant influence. Struggling to maintain a façade of normalcy, Todd hides his academic failures from his unsuspecting parents. In a twisted turn of events, Dussander then employs a tactic of his own—he coerces Todd into studying diligently to reclaim his academic standing, ominously threatening to unveil Todd’s dark obsessions and secrets to his family.
In a shocking display of manipulation, Dussander poses as Todd's grandfather, accompanying him to a meeting with the school counselor, Edward French. As they delve into the horrors of wartime atrocities, both men are haunted by their shared discussions, revealing the psychological toll on both the youthful boy and the aged war criminal. The extent of this dark mentorship leads Dussander into a sinister descent; he begins referencing the gas chambers of his past by committing acts of animal cruelty.
In a fateful night filled with dread, Dussander attempts to eliminate a hobo who witnesses him in his military uniform. However, fortune takes a turn when Dussander suffers a heart attack. Seizing the moment, Todd steps in, completing the heinous act, cleaning up the scene, and feigning ignorance by calling for an ambulance for his manipulative mentor. At the hospital, however, the walls close in when Dussander is identified as a notorious war criminal by an ex-prisoner of the camps.
Meanwhile, Todd's academic prowess skyrockets—in a matter of weeks, he transforms from a struggling student to the valedictorian of his class. As he delivers an imposing speech referencing Icarus, he articulates the poignant notion that “All great achievements arose from dissatisfaction. It is the desire to do better, to dig deeper, that propels civilization to greatness.” This moment is starkly contrasted with scenes of Dussander’s search warrant being carried out, culminating in the grim discovery of the hobo's remains in the basement, painting a picture of the duality of Todd's rising success against Dussander's impending doom.
Ultimately, Todd manages to spin a web of deceit that shields him from investigation, convincing authorities that he remained oblivious to Dussander's infamous past. Yet, within the confines of the hospital, the weight of the world crushes Dussander; upon overhearing a group of Neo-Nazis that expose his compromised identity, he takes solace in a tragic exit, choosing to end his life by inducing an air embolism.
In a chilling finale, Mr. French confronts Todd, discovering the old man he believed to be his grandfather was, in fact, a war criminal. In an unexpected twist, Todd turns the tables, utilizing blackmail to intimidate French into silence, threatening to accuse him of inappropriate advances. Thus, as Dussander lies dead in his hospital bed, Todd Bowden emerges from high school—a transformed, now fully developed sociopath, irrevocably changed by the dark interactions with Kurt Dussander.