In bustling Barcelona, Thomas and David are two Chinese cousins who run a small fast-food van and squeeze in their martial arts practice between orders. They count a bumbling ally among their circle—Moby—a Chinese assistant to a private investigator who lands a Spain-based gig after dodging debt collectors.
Moby’s first assignment is straightforward in name but tricky in scope: locate the child of a maid who once worked for a wealthy family. After they fend off a dangerous biker gang, the trio heads to visit David’s father, who is described as insane and housed in a mental institution, where they encounter Sylvia, the daughter of David’s father’s resident girlfriend. Thomas tries to nudge his cousin toward asking Sylvia out, but David chicken’s out of the moment.
That same night at the van, they learn a sharper truth: Sylvia is a pickpocket who pretends to be a prostitute to rob her patrons, and the cousins end up protecting her—and their money—from one such patron. They bring Sylvia back to their apartment, where a mix of charm and clumsy romance ensues, and the morning reveals that Sylvia, as well as the cash, has vanished.
The next day, unknown men attempt to kidnap Sylvia, but Moby unintentionally foils the plan when his actions interfere with their pursuit. Meanwhile, Moby’s employer uncovers a startling detail: Sylvia is Gloria’s daughter, and he orders a rescue. Gloria is the chambermaid linked to Sylvia’s past, and the revelation tightens the trio’s resolve.
Thomas and David soon find Sylvia again and rescue her from the clutches of her patron’s henchmen. They hire her as a waitress in their growing fast-food venture and enjoy their time with her around Barcelona, even as they continue to pursue her affections. A renewed threat arrives when the unknown men return; a high-speed chase ensues, aided by the trio’s wits and the van’s gadgets. The pursuit reveals two of the pursuers to be skilled martial artists, whom the three can’t easily defeat.
As the plot thickens, the truth about Sylvia’s lineage comes to the fore: she is the illegitimate daughter of Count Lobas, who raped his chambermaid Gloria. On his deathbed, the Count confesses this and reveals his hope to leave Sylvia and Gloria his substantial inheritance, to keep it away from his wicked brother Mondale. With a looming three-day deadline to present themselves to the lawyers, Thomas and David wrestle with the idea of helping an aristocrat, but Moby challenges them to stay committed to the mission.
The team then stages a daring infiltration of the mental institution to free Gloria and Chen, who plan to marry. After they escape, Mondale’s men strike again, overpowering the trio and kidnapping the women. In a climactic raid on the villains’ castle, Thomas, David and Moby are captured but eventually freed by Moby. A large-scale battle erupts: Thomas and David take on the two leading thugs, while Moby faces Mondale in a duel of weapons. Thomas delivers a hard-fought defeat to his opponent, David follows with a clever move to knock out his foe, and the three join forces to best Mondale in a final, valiant showdown, echoing the camaraderie of the Three Musketeers.
The film closes with Sylvia reuniting with her family, though she asks to remain on the payroll as a summer helper. Moby teases a new mission—a rescue operation for an African president—and the cousins, with good humor, decline.
