While Dave attempts to write a song for his High School reunion, Alvin breaks Simon's time machine. Frustrated by the noise, Dave takes the boys to the park where a merry-go-round sends The Chipmunks back to 1962. They meet a younger, insecure Dave who believes he might make for a better accountant than a musician. The boys don't wish to end up as accountants as well so they follow Dave home and convince his father to give Dave another chance. As Alvin writes a new song and Simon determines the exact time they must leave at the merry-go-round, Dave rests. At his prom, the boys further build Dave's confidence and energy before they rush back to the merry-go-round, barely making it in time. Once in the present they learn Dave wishes to use the song Alvin wrote.
The title is a spoof of the film Back to the Future.
This episode seems to contradict Grandpa and Grandma Seville, where Dave's parents are shown to be farmers. Here, Dave's family lives two blocks from school and his father is an accountant. However, it could have been possible Grandpa Seville bought a farm after he retired from accounting and became a gentleman farmer.