Sabrina learns that she has to spend the year mentoring a witch who doesn't have a good grasp on her magic – or lose her witch's license. Things are going as well as expected until Dreama's clumsy spell casting causes Brad to become suspicious of Sabrina and her odd new friend.

Much to Hilda and Zelda's displeasure, Sabrina invites their mother over for a visit. During her stay, the aunts get some shocking information: that their mother and father adopted them and unfortunately, start to lose their sense of identity and start to disappear. Wanting to help Hilda and Zelda, Sabrina begins an investigation to help them remember who they really are.