The island has a castaway who is much needed as a match for the chipmunks to come up against while on the island. The chipmunks end up banning together to help obtain some gold on a volcano which starts to erupt. When Dave finally finds his friends, it is during the eruption of the volcano. It is here that the chipmunks find themselves in even more trouble. One of the chipettes is kidnapped and forced to help the crazy island castaway obtain some gold before making it off the island.
The chipmunks and the chipettes must work together to help get the chipette back while working alongside of their rival. The chipettes and chipmunks make it funny for everyone watching while they sing and dance during times of struggle, but doing so in a comedy way.
If you enjoyed the first two chipmunk movies, you will definitely like this one. The best part is that the movies have followed the old cartoons. You started out on the first movie learning about the chipmunks while in the second movie, you learn about the chipettes. In the last movie, you learn about how the two of them together cause up a stir together. Overall, if you like the Alvin and the Chipmunks, this is the movie you will want to see out of all the sequels.