A family is relocated by FBI after the twin sisters stop a diamond thief with ketchup. They are blabbermouths so, as last chance, they end up in in Sydney, Australia. 2 mobsters are sent there for them and the hidden diamond.

Follow Mary-Kate and Ashely halfway around the world in this Aussie adventure jam packed with non-stop action, laughs, super spies and surfer guys. The extraordinary escapade begins when the girls eyewitness a crime and are forced to go undercover in the FBI Witness Protection Program. Unfortunately, not even the FBI can save the girls from their own blabbermouths as they blow their cover in town after town, until there's only one hiding place left - Australia!—Anonymous