Every year...Witchlings who participate in the Black Moon Ceremony are placed into covens and come into their powers as full-fledged witches...Seven isn't placed in one of the five covens. She's a Spare...Seven invokes her only option...The three Spares will be assigned an impossible task: If they work together and succeed at it, their coven will be sealed and they'll gain their full powers. If they fail...Well, the last coven to make the attempt ended up being turned into toads.