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.

Eight unsuspecting high school seniors at a posh boarding school, who delight themselves on playing games of lies, come face-to-face with terror and learn that nobody believes a liar – even when they’re telling the truth.