Dave is planning to marry his new girl-friend. While Alvin, Simon and Theodore were initially excited about it, after meeting Miles - their to-be stepbrother, and under the assumption that Dave will lose them after marriage, they now fear it. So they join hands with their enemy Miles, to stop this marriage from happening.

Will they succeed?

Rating: Green - a fun-filled non-sense affair with irritating nasal chipmunk voices. Complete entertainment till the last scene - worth a watch!