Glamorous Josephine Chesterfield (Anne Hathaway) lives in a gorgeous mansion in Beaumont-sur-Mer. She earns her money by defrauding gullible, wealthy men she meets in high-end casinos.

While traveling on a train, she spots Penny Rust (Rebel Wilson), an Australian woman who also runs scams on men. Their methods may be different, but they're both extremely talented at what they do. At first, Josephine decides to take Penny under her wing and train her. However, that doesn't work for long. Beaumont-sur-Mer is only big enough for one con woman.

They decide to make a wager. The first woman to swindle $500,000 from naïve tech billionaire (Alex Sharp) will win the turf war.