When Tabitha Two Owls was a baby, the great wizard Odelfius pronounced her "The Witch Who Wasn't". Her best friend, Jemima Jerribode, believes that Odelfius didn't intend any insult but merely forgot to finish his sentence. However, his proclamation left Tabitha doubting her identity. She has dedicated her life to proving her worth as a witch, with disastrous results. Tabitha flunks her final school exam and fails to redeem herself at the Hall of Trials. The powerful Eldwitches ban her from practising magic, leaving her adrift in a sea of disillusion. But fate has a plan for the young witch. A series of events forces her to reclaim her magical heritage and lead a battle against an ancient evil threatening to destroy the land. In doing so, she understands what being The Witch Who Wasn't truly means.