Bob Ho (Jackie Chan), an undercover operative for the CIA, decides to give up his career and marry his girlfriend, Gillian (Amber Valletta). First however, he has one more mission to complete: Gain the approval of Gillian's children. Bob volunteers to baby-sit 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.