Psychologist Detective Dr. Cross, Matthew Fox, works as a detective for the Detroit Police Department, teaming up with his childhood friend, Edward Burns as Thomas Kane, and with Rachel Nichols as Monica Ashe, who are secretly involved with each other and try in vain to keep it from Cross. Outside of work, Cross leads a happy suburban life with his mother, his pregnant wife Maria, and their two kids. Kane and Ashe share a romantic bond, which they keep carefully hidden from Cross even as they work side by side.
One night, the trio is called to investigate the torture and murder of a businesswoman named Fan Yau. From the crime scene clues, Cross determines the killer acted alone and Kane observes that the method bears the mark of a professional. A charcoal drawing depicting Fan Yau’s death surfaces in the room, prompting the team to nickname the culprit “Picasso” for the artistic, calculated precision of the crime. As the investigation unfolds, Fan Yau is linked to two other businessmen, Erich Nunemaker and Giles Mercier, and the drawing contains the letters E and N, which leads them to forecast Picasso’s next move: an attack on Nunemaker, with Mercier as the possible final target.
The team races to Nunemaker’s building and manages to prevent his assassination. In the ensuing firefight, Picasso identifies how the team is assembled and manages to slip away, even after Kane shoots him in the shoulder. The question of safety looms large, and Kane asks Cross whether Picasso will target them or their loved ones next. Cross offers a cautious assessment, arguing that Picasso is a professional with a narrow focus who would not stray from his list—a conclusion that soon proves itself incorrect as Picasso immediately pivots to seek revenge against them.
Meanwhile, Cross and his wife Maria are out for a celebratory dinner—news that they are expecting their third child prompts Cross to consider a different path. He contemplates taking an FBI position for better hours, pay, and benefits that would give him more family time, while Maria worries about leaving Detroit for Washington, D.C. Their plans are interrupted when Picasso calls Cross using Ashe’s phone number, sending a photo of Ashe in torture to taunt him. Enraged, Cross and Ashe’s personal tragedy becomes a catalyst for Cross to taunt Picasso, while Picasso—who has had a sniper trained on Cross all along—reveals his true aim: to kill Cross’s wife.
Driven by grief and vengeance, Cross and Kane intensify their pursuit, tracking down the chemist who supplied Picasso with the drug used on Fan Yau and Ashe. When they pinpoint Picasso’s likely location, they learn he intends to assassinate Mercier. Picasso launches an RPG toward Mercier’s convoy, appearing to kill him, and the chase reaches a climactic confrontation in a church rafters. The confrontation ends with Picasso's death, but not before he reveals a bitter truth: he has shaped Cross into the person he has become.
Afterward, Cross uncovers a deeper conspiracy: Mercier is still alive and has orchestrated the attacks all along. Mercier hired Picasso to fake his own death by using a man named Cloche to escape entanglements with the German government. With Mercier hiding out in Indonesia, Cross contacts him to reveal that his own assistant has betrayed him for immunity. Indonesian authorities converge to arrest Mercier on drug-smuggling charges, a crime punishable by death in Indonesia. With justice served in mind and resolve renewed, Detective Dr. Cross and Kane agree to join forces with the FBI, promising to continue their pursuit of threat and justice together.
