John Gregory, who is a seventh son of a seventh son and also the local spook, has protected his country from witches, boggarts, ghouls and all manner of things that go bump in the night. However John is not young anymore, and has been seeking an apprentice to carry on his trade. Most have failed to survive. The last hope is a young farmer's son named Thomas Ward. Will he survive the training to become the spook that so many others couldn't? Should he trust the girl with pointy shoes? How can Thomas stand a chance against Mother Malkin, the most dangerous witch in the county?