Beckett Redfellow Glen Powell sits on death row, speaking with a priest as he tries to explain how his life spiraled into murder and what pushed him to this final moment. As a child, he is raised by his single mother, Mary, who is exiled from the wealthy Redfellow clan for choosing to keep her teenage pregnancy. He forms a surprising bond with the more affluent Julia Steinway Margaret Qualley, a relationship that will pull him deeper into the family’s tangled web. Before Mary’s untimely death, she makes sure Becket understands that he should fight for the life he deserves, embedding a cruel sense of destiny in his young mind.
As an adult, Becket encounters a married Julia and suffers a demotion from his job as a suit salesman, an upheaval that seems to push him toward a darker path. He resolves to wipe out the remaining Redfellows to claim the inheritance and the sprawling fortune that comes with the name. He begins by killing his cousin Taylor, and at the funeral he meets Taylor’s father Warren Bill Camp, who offers Becket Taylor’s old job at a financial investment firm. Becket then moves to eliminate Noah, planning his murder while quietly befriending Noah’s girlfriend Ruth Jessica Henwick. After Becket shoots Noah, FBI agents close in, discussing the suspicious deaths but stopping short of naming him as a suspect. Becket pretends he is unsure whether he is eligible for the inheritance, keeping his motives hidden beneath a calm exterior. Julia later steps into Becket’s office, claiming her husband Lyle is broke and asking for a loan, which Becket refuses, keeping his own ambitions intact.
Becket and Ruth’s relationship deepens as they begin dating and even move in together. Yet his ruthless ascent continues: he kills three more Redfellows—Steven, Cassandra, and MacArthur—while advancing in his career and securing a life he thinks he deserves. Warren suffers a heart attack and dies, leaving Becket with one last living Redfellow to confront: his aging grandfather Whitelaw Ed Harris. The household collides in a tense dinner invitation at Whitelaw’s mansion on the night of Becket and Ruth’s engagement party. Julia reveals she has damning evidence of Becket’s murders and will expose him unless he sends money to her husband Lyle. Becket complies, delivering a check to Lyle and abandoning the party to confront Whitelaw in his home. Whitelaw traps Becket and tries to kill him with a shotgun, but Becket defends himself and ends Whitelaw’s life, becoming the sole heir to the fortune.
A celebratory party soon turns grim as FBI agents arrest Becket for the murder of Lyle, who was found stabbed to death in his office with a letter opener that Becket had touched during the money delivery, leaving fingerprint evidence that seals the charges.
Only one day remains before Becket’s scheduled execution when Julia visits the jail. She reveals a suicide note from Lyle that had been withheld from the trial, but only if Becket signs over the entire Redfellow fortune to her. Becket agrees, and Julia releases the note, clearing his name. Ruth waits outside the prison and returns Becket’s mother’s locket before departing without a word. Becket then sees Julia waiting with the Redfellow family driver, and the two depart together toward the family mansion, where a new, uncertain future awaits them.
