Cosmo, a witch-cat, is delighted that evil Sybil -- the most terrible of witches -- is safely in prison. In fact, she's even fitted with a special tag, which means that if she and her cronies try to escape they will be turned into frogs. But then mysterious goings-on are reported in Witch News. Baby witches are being visited by a strange new health visitor -- and having their long, curly toenails clipped and stolen! Something sinister is afoot. Could it be that Sybil and her criminal cauldron are at work again?