Harriet "Harry" and Peter Fox are a dynamic duo of British con artists residing in London, plotting an elaborate jewel heist in Los Angeles while evading the wrath of a dangerous female gangster, Irina Solokov. Earlier, Harry had received a substantial sum from a nun after a questionable cocaine deal. However, both Harry and Peter squander their earnings on gambling and substances, leaving them broke and desperate. To escape their declining fortunes, they set their sights on Los Angeles, hoping to regroup and formulate their next plan.
Upon their arrival in the City of Angels, they reconnect with an old acquaintance, Sidney, a morally ambiguous priest who supplements his income with illegal activities. In a twist of fate, Harry and Peter strike a deal with Sidney, who offers them $40,000 to transport a shipment of opium. However, as tensions rise, Peter discovers that Irina is pursuing them not merely for financial reasons but also due to unanswered affections for Harry, harboring a deep disdain for Peter.
Sidney, ever the opportunist, covertly informs Irina about the bounty on Harry and Peter's heads, prompting her to enlist her henchman and head to L.A. Meanwhile, while hiding out in a plush Beverly Hills hotel, Peter encounters his ex-wife, Jackie, who is now married to Gabriel, a film director entangled in a secretive affair with both Gina, a family member of Jackie's, and Vivienne, a demanding Latina actress.
Obsessed with Jackie’s extravagant £5 million blue-stone ring, Harry and Peter concoct a plan to steal it as a means to repay Irina for their failed drug deal. They devise a clever scheme to create a counterfeit version of the ring that they would switch during a dinner party at Jackie and Gabriel's residence. Unfortunately, their plans are thwarted by the inebriated Gabriel and Vivienne, who create chaos just as they attempt to execute their heist.
When Irina tracks down their location, Harry and Peter, in a panic, seek refuge in Jackie's home, where Harry poses as a dog whisperer—but only succeeds in sending mixed signals to Jackie. Tensions boil over when Jackie and Gabriel attend an awards ceremony where Gabriel, despite winning the Best Director accolade, publicly disses Jackie by proclaiming his love for Vivienne during his acceptance speech. This betrayal ignites a furious conflict, culminating in Jackie tossing her ring into Harry's glass of wine, creating an unexpected turning point.
The situation escalates into a shootout as Harry and Peter make their escape from the mansion, racing to the airport to evade Irina and her henchmen. Amid the fray, Harry manages to wound Irina and hand her the fake ring they intended to swap out. However, when they arrive at LAX, the duo discovers a shocking reality: they mistakenly brought the counterfeit instead of the genuine article. With no recourse but to flee, Harry and Peter board a flight to Brazil, leaving behind their entanglements and any remaining wealth, but finally escaping the clutches of their gangster pursuer.
