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.