As Halloweentown prepares to celebrate its 1,000th anniversary, Marnie Piper and her brother Dylan return to Witch University, where trouble is in session from the Sinister Sisters and from someone who's plotting to use Marnie's powers for evil.

This is a movie about two scientists who invent a time machine. A critical part falls out of the time machine before they get into it to test it. Nothing seems to happen at first, but when they wake up the next day they are regressing in age (physically and mentally).