Earl Brooks, played by Kevin Costner, is a prosperous businessman celebrated by the Portland, Oregon Chamber of Commerce as the "Man of the Year." However, beneath this veneer of success lies a dark secret: Brooks is infamous as the "Thumbprint Killer," a serial murderer grappling with a dangerous addiction. For the past two years, he has resisted his urges by attending 12-step meetings, but the pressure to kill surges once again as his sinister alter ego, Marshall, grows more assertive.
In a moment of desperation, Brooks succumbs to his violent impulses, brutally murdering a couple in their apartment while they are in the midst of intimacy. True to his meticulous methods, he leaves their bloodied thumbprints on a lampshade, cleanly executing his plan with precision, including ensuring the doors are locked before his departure. However, Marshall notices that the couple's curtains were left open.
Unexpectedly, Brooks' daughter, Jane (played by Danielle Panabaker), returns home after dropping out of college. Eager to join her father's company, she unwittingly complicates Brooks' life further. On the same day, a man known as "Mr. Smith" (Dane Cook) confronts Brooks at work, blackmailing him with incriminating images from his recent murder. Despite his initial reluctance, Brooks finds himself drawn into a pact with Smith, agreeing to take him along on a murder spree.
Complications arise when Mrs. Brooks reveals that Jane is pregnant. Things get even more tangled with the arrival of detectives from Palo Alto, inquiring about a hatchet murder connected to Jane's previous life at college. Brooks and Marshall suspect Jane may be involved and even consider sacrificing her freedom to keep her from descending into a life of crime like their own. Ultimately, seeking to protect her, Brooks devises a plan to create a separate serial killer myth, committing another murder in Palo Alto to distract law enforcement from Jane's potential culpability.
As the weight of his crimes bears down on him, Brooks finds himself wanting to end his killing spree while devising a plan to evade capture and protect his family. He crafts a narrative to pretend he is terminally ill, planning to vanish entirely. Researching the relentless Detective Tracy Atwood, who is entangled in her own tumultuous divorce, he sets his sights on ensuring that both her ex-husband, Jesse Vialo (Jason Lewis), and his lawyer (Reiko Aylesworth) become his next victims.
In a shocking turn of events, Smith, in a moment of panic at the murder scene, accidentally leaves behind crucial DNA evidence, while his schemes lead to a fateful confrontation with Brooks. Brooks cleverly outmaneuvers Smith and ultimately turns the tables on him, saving his own life while ensuring his identity remains concealed.
As the authorities mistakenly celebrate Smith as the Thumbprint Killer, Brooks resumes his facade of normalcy. A call to Detective Atwood reveals a connection between the two, illuminating a chase that may never end. Brooks' haunting fear of his daughter becoming like him surfaces in a nightmare, illustrating the inescapable grasp of his dark legacy.
