All Betty Widdershins wants is an adventure--one that takes her far away from Crowstone, the gloomy island where she's always lived. But instead of an adventure, Betty and her sisters, Fliss and Charlie, are given of a set of magical objects, each with its own powers: a scruffy carpet bag, a set of wooden nesting dolls, and a gilt-framed mirror. And these magical objects come with their own terrible secret: the sisters' family is haunted by a generations-long curse that prevents them from ever leaving their island--at the cost of death.

The sisters set out to break the curse and free their family forever. But after stumbling upon a mysterious prisoner who claims to be able to help them, they find themselves in great danger. And in order to break the curse--and stay alive--they must unravel a mystery that goes back centuries, one that involves shipwrecks, smugglers, and sorcery of the most perilous kind.