Box of Tricks, Book 4
Sophie and Katy shouldn't be friends: witches and witch-hunters just aren't meant to get along! Now that their friendship is out in the open, both girls are in danger. But if they stick together, they feel like they can overcome anything.
Then Katy starts acting strangely mean. Sophie is totally confused: it's like her BFF has had a personality transplant. And that's not possible . . . is it?