A woman claiming to be Karen's long-lost sister shows up unexpectedly on Gwen's doorstep. Amanda and Gwen quickly hit it off, but Harve and Louise harbour growing suspicions about their mysterious guest. Also a practitioner of magic, Amanda offers Gwen a free-spirited and fun-loving alternative to Merlin's strict regimen. Faced with an opportunity to move in with Amanda, Gwen must make a difficult decision about her future. Meanwhile, Josh's increasing suspicions about Gwen and Michael's relationship lead him to set up a double-date: he and Gwen, along with Tasha and Michael. But his jealousy compels Gwen to reach an inevitable conclusion: she has to do the right thing and break up with Josh. Meanwhile, Tasha - who has learned the truth about Michael's lack of feelings for her - blames Gwen, and breaks off all contact.

Gwen finds herself isolated as she has broken off with Josh and Tasha is no longer speaking to her. But this is a stronger, more focused Gwen who is now determined to learn magic and save her mom. Meanwhile, Michael - without Gadowain's protection as long as he wears an iron bracelet - finds himself manipulated into a fight at school. Gadowain offers Gwen a deal: get Michael to remove the bracelet, and Gad will tell Gwen how to rid Karen of the demon.

When a faerie dog known as Black Angus crosses Tasha's path, legend dictates that she has only a day to live. Gwen, still on non-speaking terms with Tasha, must exercise her greatest magical feat to date: turn back time to save Tasha. Time travel turns out to be more complicated than she expects, and she must find a way to thwart the forces of destiny if she plans on saving Tasha. In the end, Gwen succeeds, but - because time has replayed - Tasha doesn't realize Gwen has saved her life, and still refuses Gwen's friendship.