Eighteen-year-old Eff must finally get over believing she is bad luck and accept that her special training in Aphrikan magic, and being the twin of the seventh son of a seventh son, give her extraordinary power to combat magical creatures that threaten settlements on the western frontier.
In 1817 in England, two young cousins, Cecilia living in the country and Kate in London, write letters to keep each other informed of their exploits, which take a sinister turn when they find themselves confronted by evil wizards.
In an alternate frontier America, Eff must travel beyond the Great Barrier and come to terms with her magic abilities--and those of her twin brother--to stop the newest threat encroaching on the settlers.
Eff learns about magic and ways of looking at the world when she embarks on a government expedition with her twin brother, her best friend, and her mentors Professor Torgeson, Wash Morris, and Professor Ochiba.