The Chipmunks have just cut a new album. However, Dave gets a call that there are glitches in the recording, so he will probably be stuck at the recording studio all night helping the technicians iron out the bugs. The boys (especially Alvin) are pleased to have the house alone, but Dave beats them to the punch by hiring a babysitter, due to the fact that they trashed the house last time! They are then horrified to see that the babysitter Dave hired is not some teenage cutie, but a stern German woman named Helga! She has zero tolerance for the antics of The Chipmunks, ordering them to clean the house and eat a yukky vegetable dinner.
Alvin convinces Theodore and Simon that she is evil. Simon says that although Helga is hard-nosed, Alvin cannot accuse her of being evil. Alvin proves his point by turning on the TV, which is showing a mystery movie which shows the babysitter as the culprit. Terrified, the boys run away, but Helga captures Theodore, soon catching Alvin and Simon as well. When Alvin and Simon are reunited with Theodore, he was not tortured as they thought, but had been helping Helga bake a cake. They learn that the babysitter is a trainee and is afraid she is going to fail her entry test. After these facts are learned, the boys help her so she can get her job, only with the agreement that she could be their babysitter for a while and they would get to stay up late.
- When Alvin and Simon are captured by Helga and escorted to the kitchen, Simon says he forgives Alvin for everything. Alvin asks if a debt of 75 cents is also forgiven, to which Simon responds "Well, almost everything!" For reasons unknown, this small scene was censored from the DVD release.
- Part of the Alvin and the Chipmunks: Hair-Raising Chipmunk Tales VHS.
- Part of the Trick or Treason and Halloween Collection DVDs.