When a critical mission to recover a stolen suitcase bomb goes horribly awry, CIA agent Kevin Pope, played by Chris Rock, meets his untimely demise. Operating undercover as an antiquities dealer under the alias Michael Turner, his untimely death sets off a chain reaction. In a bid to salvage the operation, the CIA learns of Pope's twin brother, Jake Hayes, also portrayed by Chris Rock, who was separated at birth when their mother tragically passed away during childbirth. As a result of a severe lung infection, doctors initially deemed Hayes unlikely to survive, leading to the fateful separation.
Living a life of hustling through chess games, scalping tickets, and performing at small clubs in Jersey City, Hayes finds it increasingly difficult to get by. Meanwhile, his girlfriend Julie, played by Washington, grows discontent with his lack of ambition and decides to relocate to Seattle, Washington.
The CIA, realizing the potential of Hayes' involvement, convinces him to step into his brother's shoes and begins training him for a vital mission slated to unfold in Prague, Czech Republic. However, they quickly become apprehensive about his unsophisticated demeanor. In a tense exchange, Agent Oakes, acted by Anthony Hopkins, expresses his distrust towards Hayes. Despite the initial hiccups, the CIA places Hayes in his brother's former Manhattan apartment to lure in the men responsible for Kevin's death.
During this precarious setup, Hayes faces an attack but manages to escape unscathed. Seeking guidance, he turns to his foster mother only to be intercepted by Oakes, who encourages him to see the mission through.
Upon arriving in Prague, Hayes encounters the individuals attempting to sell the suitcase bomb under the guise of his deceased brother. Among them is Adrik Vas, an ex-Russian Army Colonel linked to the Russian Mafia. After returning to their hotel, Hayes meets his brother's ex-girlfriend Nicole, who mistakenly believes he is Kevin. Following a dinner together, Nicole soon realizes the truth and resumes her assignment with CNN covering the Balkans.
As Hayes embarks on his mission with Oakes, they connect with Adjanic and successfully acquire the arming codes necessary for the bomb. However, the deal takes a perilous turn when Vas' associates betray him with a rival buyer from a Greek terrorist group. When these terrorists realize they cannot detonate the bomb due to the absent codes, they kidnap Julie. Driven by love, Hayes surrenders himself to save her, leading to a race against time to recover the codes and prevent catastrophe.
The climax escalates at Grand Central Station, where the astute team locates the bomb with the countdown underway. In a thrilling showdown, Oakes leaps to Hayes' rescue, eliminating two terrorists with swift precision. As Hayes approaches the bomb to disarm it, the tension peaks when Andre, the rival buyer, takes Julie hostage. With a quick-witted distraction, Hayes feigns shooting Oakes, which allows them to overpower Andre, eventually leading to his demise. In a nail-biting moment, Hayes successfully disarms the bomb just seconds before it detonates.
In the film's poignant conclusion, Hayes pays his respects at a memorial for fallen secret agents, visiting his brother's grave. Later, during his wedding, Oakes approaches Hayes with a warning about a vengeful criminal who has escaped from prison, seeking retribution against Kevin Pope. The twist—since Kevin is deceased and Hayes allowed himself to be mistaken for his brother, the pursuit now includes him. As anxiety grips him, Hayes demands that Oakes protect him, only to discover it’s a jest, with Oakes humorously revealing he merely came to celebrate the wedding.
