Alvin is distraught when David goes of on a solo business trip to Europe without him and his brothers Simon and Theodore (well more him anyway). Yet soon later they and the Chippettes – Brittany, Jeanette and Eleanor, find themselves agreeing to participate in an around the world hot-air balloon race; collecting hidden chipmunk dolls and depositing them along the way to mark their progress. But what both teams don’t know is that they are really being used to smuggle the diamonds hidden in the dolls around the world by the ones who set up the race, international crooks Klaus and Claudia.