Teddy Jackson, played by Kevin Hart, is an aspiring fitness enthusiast who constantly struggles with his attempts to promote his health ventures. In the opening scenes, he is seen trying to create a promotional video using elastic bands, a sweatsuit, and a makeshift non-contact boxing routine — but all of his efforts fall flat, highlighting his recurring missteps and tendency to "teddy things up."
Meanwhile, somewhere in the desolate desert, a deadly assassin known only as "The Man From Toronto", portrayed by Woody Harrelson, is seen interrogating a suspect in a cabin. The assassin prepares to harm his target with a hot knife, but the suspect, overwhelmed by fear, readily reveals the information Toronto seeks. The scene is interrupted when the suspect is quickly shot and killed by an unseen figure, revealing a world of clandestine murders and covert operations.
Back in the city, Teddy is preparing to celebrate his anniversary with his wife, Lori, played by Jasmine Mathews. Despite her love for him, Lori is well aware of Teddy’s reputation as a troublemaker and a consistent screw-up — so much so that her coworkers have a nickname for his blunders: “Teddying things up.” Teddy plans a romantic getaway at a cozy Airbnb, but due to a misprint caused by a "low toner situation," he cannot read the address correctly and ends up at the wrong cabin.
At work, Teddy’s boss, Marty, played by Martin Roach, is frustrated because Teddy is inept at handling important details — he has printed gym flyers without including the address or contact number, making him seem even more unprofessional. Unfortunately, Marty has no choice but to fire Teddy, leaving him jobless and uncertain about his future.
Meanwhile, The Man From Toronto returns home and is contacted by his handler, played by Ellen Barkin. Although Toronto is just looking to relax, she informs him of a lucrative upcoming contract worth $2 million, which pulls him back into the dangerous world of assassination.
Teddy and Lori’s anniversary day takes a chaotic turn when Teddy visits a spa to treat her, but after dropping her off, he mistakenly goes to the wrong location based on a printed reservation. This error leads him directly to the cabin where Toronto is supposed to meet a target. The house’s henchmen, mistaking Teddy for Toronto, take him to the basement, sparking a series of frantic attempts by Teddy to stay calm and diffuse the situation. However, the terrified hostage in the basement ends up revealing crucial information, which blows his cover.
Shortly after, a flash grenade detonates, and FBI agents storm the house, apprehending Teddy along with the rest. During interrogation, agents quickly conclude that Teddy is not the infamous assassin, but they need Toronto’s expertise to track down Sebastian Marin, a disgraced former Venezuelan Colonel played by Alejandro De Hoyos, who attempted a coup that was thwarted by U.S. intelligence. Marin and his wife, Daniela, played by Lela Loren, managed to escape but remain dangerous.
The FBI wants Teddy to continue pretending to be Toronto, to get close to Marin and bring him down. Agent Santoro, portrayed by Jencarlos Caneda, is assigned to watch Lori, who, feeling neglected, spends time with her friend Annie, played by Kaley Cuoco. Teddy, hiding his firing from Lori, claims he was called away on a work conference, adding to his ongoing lies.
Toronto, meanwhile, tracks Teddy down, driven by the evidence left on Teddy’s fitness ads. Seeing how mismatched and hapless Teddy appears in comparison, Toronto is skeptical but begins to understand the situation. After confronting Daniela, Toronto is coerced into joining the operation, leading them to a secret hangar and onto a plane bound for Puerto Rico. Mid-flight, Toronto reveals his true identity, fighting off Marin’s henchmen and saving Teddy from falling out of the plane.
The duo crash-land in a field after the plane explodes, and they quickly realize they need to find someone named Mr. Green, believed to hold vital information. The story takes them to a tech convention where Teddy, coached by Toronto, must interrogate four suspects to identify Mr. Green. Despite Teddy’s accidental slashes and puking on suspects, he manages to identify the right person — but must also fend off an attack by Miami, an assassin played by Pierson Fode, who is determined to eliminate them.
Throughout their journey, the duo develops a comical yet tense camaraderie. Teddy learns to act more confident, and Toronto begins to open up about his regret over past jobs and his hopes to open a restaurant one day—an act of moving away from murder. Their pursuit leads them to a high-stakes showdown in Washington D.C., involving a staged dinner with Lori and Annie where more trouble ensues, including a shootout with Miami, who shoots Teddy in the leg but is ultimately subdued.
As the chase heats up, Toronto and Teddy infiltrate Marin’s hotel room, hoping to arrest him for his previous attempted coup. They manage to neutralize the threat and arrest Marin and Daniela, although The Handler and Miami escape during the chaos. Teddy’s quick thinking results in him taking the payment meant for Toronto, symbolizing a partial victory for Teddy's resourcefulness.
As Teddy returns home to find Lori gone, she confesses she’s leaving to her mother’s because she’s unsure of what’s happening with him. He races to catch her at the train station, where Miami confronts him again. Toronto joins just in time, rescuing Teddy and fighting off multiple assassins, including notorious killers like The Man From Moscow, The Man From Tokyo, and The Men From Tacoma. Their encounter culminates in a fiery confrontation back at Teddy’s old gym, where Toronto exterminates the assassins.
The climax comes in a chase sequence at a factory, with The Handler chasing after them. Ultimately, Teddy and Toronto succeed in ending her threat when Teddy pushes her into a boiling vat, ending her reign of terror. Teddy then rushes to reconcile with Lori, finally confessing and apologizing for his past mistakes. Reunited, they share a heartfelt moment, planning their future.
However, the story closes on comic chaos: Teddy’s car, left on the train tracks in his haste, is struck by a train, sending the money flying and prompting police to tackle him. A year later, Teddy and Lori are expecting a baby, building a new chapter of their life. Toronto, having opened his own restaurant, is now dating Annie, still haunted by his past but striving for a better future. Meanwhile, his desire to eliminate Teddy still lingers, hinting that their story may not be over yet.
