The adventure begins when David Seville takes off for Europe on a solo business trip, leaving the disappointed boys at home with Miss Miller. All three chipmunks dream of world travel, but Alvin has a foolproof scheme to make it happen. Before Simon can say "Are you out of your mind!" Alvin has entered them in a daring hot-air balloon race around the world against the Chipettes - Brittany, Jeanette and Eleanor. Both the Chipmunks and the Chipettes get more than they bargained for when the race turns out to be a front for a pair of international diamond smugglers. The Chipmunks embark on a world-class voyage with the masters of music and mischief.