Abigail "Billie" Harper is moving from her independent school to the local school. A couple of weeks before the new term she is in the wrong place at the wrong timed is cursed by 10 year old Fawnie. Fawnie is the seventh child of Enoch Lovell, who himself is a seventh son and whose father was also a seventh son. Fawnie has magic powers so rare and potent they have hardly ever been seen before. So Billie is cursed, she's moving to a new school and has the added complication that because of the way her brain works her mother thinks she's a boy.