Entrapment (1999)

Insurance investigator Virginia "Gin" Baker (Catherine Zeta-Jones), looking into a stolen Rembrandt painting, suspects that accomplished thief Robert "Mac" MacDougal (Sean Connery) is responsible. She decides to go undercover and help Mac steal an ancient artifact. When a suspicious Mac confronts Gin about her real intentions, she claims that she is, in fact, a thief and that the insurance job is a cover. To prove it, she proposes a new target that could net them $8 billion.