The film opens with a thrilling montage showcasing Jackie Chan's iconic stunts and action sequences from his previous films, including The Tuxedo and Operation Condor. Following this nostalgic introduction, we meet Bob Ho, portrayed by Jackie Chan, as he wakes up to begin his day. Nearby, his next-door neighbors, Gillian and her three children, also start their typical morning routine. Gillian, played by Amber Valletta, is the loving mother of Nora— the youngest daughter with a flair for femininity (played by Alina Foley), intelligent Ian (Will Shadley), and the typical teenager Farren (Madeline Carroll).
As Gillian takes her children to school, Bob, who poses as a mundane pen importer, offers to help her with the trash. The budding romance between Bob and Gillian is apparent, but her children are less than thrilled about the idea, viewing Bob as unexciting and nerdy. During a dinner date to celebrate three months together, Bob attempts to confess his secret identity as a CIA agent but is interrupted when he receives a phone alert that requires his immediate attention.
Bob, alongside his colleague Colton James, portrayed by Billy Ray Cyrus, sneaks into an American oil refinery to thwart villainous plans aimed at contaminating the oil supply. After the successful operation, Bob expresses his wish to retire from espionage and settle down with Gillian. However, his past life proves difficult to escape. When Gillian informs Bob that her father needs urgent medical attention and she’ll be out of town, she asks for Bob's help in babysitting her kids. Bob seizes this as an opportunity to bond with the children and improve their perception of him.
As Bob organizes his belongings to stay with the family, Ian unintentionally stumbles upon crucial files inadvertently downloaded to his iPod, mistaking them for music. Meanwhile, the escaped villain Poldark seeks revenge on Bob, unaware that the files have ended up with him. The threat escalates when Bob and the children are attacked by a Russian spy named Larry while at a restaurant. Bob reveals his true identity as a former CIA agent to the children while defending them.
In a race against time, Bob learns that the watch he kept—a suggestion from his colleague Glaze—has become a tracking device for the remaining adversaries. After a series of narrow escapes, Bob tries to assure Gillian of their safety, but their relationship is shaken when she learns the truth about the dangers they faced. Not wanting to stay dormant, Ian, dressed in makeshift spy gear, rushes to aid Bob, believing in his heroic capabilities.
As the climax builds, Bob confronts Poldark and his henchmen in an abandoned factory while the children manage to escape as Bob fights valiantly. With clever resourcefulness shown with Ian's bicycle, Bob engages in a spectacular showdown with the villains. After defeating them and reuniting with the kids, they find themselves back home just in time for Halloween.
As chaos erupts with the villains launching a surprise attack, Bob calls for CIA assistance while collaborating with the children. Just as the enemies are on the verge of capturing them, help arrives from Colton and the CIA, neutralizing the threat. After everything calms down and the dust settles, a touching moment unfolds as Gillian decides to stay with Bob despite their trials. In a heartwarming conclusion, we glimpse the couple's wedding, where Bob indicates he still has another secret to share, leaving both the audience and Gillian intrigued about his true identity.
