Keller Dover, portrayed by Hugh Jackman, is a deeply religious figure struggling to keep his carpentry business afloat. During a Thanksgiving gathering with his family at their neighbors' home, the Birches, a tragic event unfolds when his young daughter, Anna Dover, and Joy Birch, go missing. The situation escalates as a police search leads to the discovery of a suspicious RV parked near a gas station adjacent to a wooded area. Detective Loki, played by Jake Gyllenhaal, arrives on the scene and questions Alex Jones, the RV's driver, but after a chaotic attempt to flee, Alex crashes and is arrested.
As Loki delves deeper into the case, he starts interviewing local sex offenders and stumbles upon a shocking find: a corpse tied to a chair in a local priest's basement. The priest, claiming to have killed the man after he confessed to murdering children, mentions that the deceased was "waging a war against God." This revelation leads Loki to take note of a mysterious maze pendant found around the corpse's neck.
Despite facing aggressive interrogation, Jones, who is later found to have the mental capacity of a ten-year-old, offers little information that connects him to the missing girls. The forensics team finds no incriminating evidence in his RV, resulting in his release. However, during a tense confrontation outside the police station, Jones chillingly tells Dover, "They didn't cry until I left them," going unheard by others present. Dover's conviction that Jones possesses crucial knowledge about his daughter's whereabouts leads him to kidnap and imprison Jones in an abandoned building, with the reluctant assistance of Joy's father, Franklin, played by Terrence Howard.
As the situation grows darker, Dover and Franklin begin to torture Jones for information, yet their efforts yield no results. Overcome with guilt, Franklin confides in his wife, Nancy, played by Viola Davis, about their actions. Initially, she supports Dover's relentless pursuit of answers, refusing to intervene amidst the torment.
While a candlelight vigil for the girls is being held, Loki spotlights a hooded figure acting suspiciously. After a brief chase, Loki draws a composite sketch of the suspect, which is later released to the public. Meanwhile, a break-in at Grace's home draws Loki's attention, where he discovers evidence suggesting that Keller is hiding something. Further investigation into the background of Alex leads Loki to uncover unsettling truths about Keller's familial history.
The plot thickens when Loki eventually apprehends a suspect named Bob Taylor, whose creepy home reveals alarming details about his past and links him to the abduction. Despite Taylor's arrest and confession, Keller's obsession with finding his daughter drives him to continue his brutal treatment of Jones. In a desperate turn of events, Keller learns from Holly Jones, played by Melissa Leo, that she masterminded the abduction to enact revenge against the world for the loss of her own son to cancer.
As tensions mount, the film spirals into chaotic confrontations, culminating in a gripping climax where Loki saves Anna just in time. Yet, as the dust settles, Keller's fate hangs uncertain, compelling viewers to reflect on the devastating consequences of desperation and the moral complexities intertwined in the search for truth and justice. The chilling conclusion leaves audiences with the echo of a faint whistle, resonating as a poignant reminder of the pain endured and unanswered questions that linger in the dark.
