A mysterious white horse, a quirky parrot, a haunted house, an ancient curse, something frightening in the attic... A summer holiday turns into a nightmare when the Mallory family rents a shabby cottage in a remote corner of Ontario's Rideau Lakes. Seventeen-year-old Chip Mallory and his sixteen-year-old sister Lee are persuaded to go along on "one last family vacation" with their parents before they get caught up in their own lives again.

But when a great storm comes up, and the family moves to an island in the lake, all their technology can't save them from an encounter with an ancient curse. Chip and Lee are drawn into a complex web of past and present; they struggle to make sense of these ancient mysteries, aided by a visiting anthropologist, a poor backwoods girl, and a beautiful young woman who lives on an island with her reclusive and powerful grandfather.