The story unfolds in February 1979, set against the backdrop of a steel plant in Lillian, Ohio, following the tragic accident that claims the life of Elizabeth Lamb, portrayed by Caitriona Balfe. Her husband, Deputy Jackson Lamb (Kyle Chandler), is engulfed in grief, but the community’s concern primarily revolves around their son, Joe Lamb (Joel Courtney). In a fit of rage, Jackson holds Louis Dainard (Rainn Wilson) responsible for the accident, forcibly removing him from their home and stashing him in his squad car. Witnessing this from a distance, Joe's attention is drawn to a silver locket clasped tightly in his hand.
As summer rolls in, Joe's friend Charles (Riley Griffiths) enlists Alice Dainard (Elle Fanning), Louis's daughter, to star in a Super 8 film they've been working on for a film festival. That evening, Joe joins Charles and their friends—Cary, Preston, and Martin—at the Lillian Train Station. Here, they aim to shoot a scene involving a detective and his wife, with Joe developing a crush on Alice as her performance brings her to tears. The thrilling moment is suddenly interrupted by an approaching train, leading Charles to urge his friends to capture this moment to enhance their film's production value.
However, the scene takes a catastrophic turn when Joe notices a white truck approach the tracks, resulting in a massive train derailment. The group narrowly escapes and discovers peculiar white cubes amidst the wreckage, one of which Joe picks up. In a shocking revelation, they also find the body of their local science teacher, Dr. Woodward (Glynn Turman), clutching a map. Joe is startled when the other adult threatens them with a gun, demanding they remain silent about the incident.
The next day, while developing the film, Joe reassures Charles of his commitment to complete their project, despite Charles’s doubts about Alice’s willingness to help. After confronting Alice's father, Joe persistently charms Alice into joining their film effort. Back at the crash site, Joe discovers the train's Air Force insignia and examines the map Dr. Woodward had, revealing a red line zigzagging across the nation.
Simultaneously, Jackson is on a mission to uncover the truth behind the train wreck and the government’s subsequent involvement. His inquiries lead him to a military presence in Lillian and the mysterious General Nelec (Noah Emmerich), who refuses to disclose the purpose of the Operation: Walking Distance.
As chaos erupts in town with the disappearance of Sheriff Pruitt (Brett Rice) and various locals, Jackson grows increasingly alarmed. Reports of missing pets, appliances, and even electrical components surface, enhancing the veil of mystery surrounding the government operations. Compounding the urgency, the military mobilizes to the area, igniting Jackson’s determination to find answers.
Amidst this turmoil, the creature from the train crash begins its emergence, catching Joe and his friends in a web of confrontation between the military and the creature. They delve into the depths of discovery at Dr. Woodward's storage, unveiling records about the creature who crash-landed in 1958, a being that seeks to return home after being subjected to military experiments.
After a harrowing series of events, which includes a chaotic military scene and a desperate need to rescue Alice from the creature’s lair, Joe bravely faces the menacing entity. Using ingenuity, he orchestrates a distraction to save Alice and Sheriff Pruitt, leading to a climactic confrontation where Joe confronts the creature, striving to mend its perception of humanity.
In a heartwarming culmination, as Jackson and Louis reconcile, Joe relinquishes the past tied to his mother, represented through the locket, allowing the creature to ascend back to the sky in its makeshift spaceship, while the townsfolk witness an awe-inspiring spectacle.
As a delightful post-credits extra, viewers are treated to a glimpse of Charles’s completed film, titled 'The Case', which subverts expectations in a thrilling narrative about a detective grappling with the horrors of a zombie outbreak!
This tale is a captivating blend of adventure, mystery, and heart, revealing the trials of youth, the weight of loss, and the unfathomable connection we share with the unknown.
