Bob Ho (Jackie Chan), an undercover operative for the CIA, decides to give up his career and marry his girlfriend, Gillian (Amber Valletta). However, before Bob can do that, he has one more mission to complete: gain the approval of Gillian's children. Bob volunteers to babysit when Gillian is called away, but the operation hits a snag when one of the kids mistakenly downloads a top-secret formula, and a Russian terrorist takes aim at Bob's prospective family.