Lying far out in the Atlantic, roughly three hundred kilometres southeast of mainland Nova Scotia, Sable Island is a thin, crescent-shaped ribbon of sand adrift in the open ocean. Its name is taken from the French word for sand, a fitting label for a place that is little more than a great dune rising from the sea. Mainlanders and the handful of visitors who reach it are drawn by its wild horses, its stark beauty, its long and often tragic past, and the surprising range of life it manages to support. For as long as anyone can remember, the island has turned on the moods of the surrounding water, and countless stories of the sea have grown up around it.

Sable Island holds a distinction shared by few places on the continent: it is one of the largest sandbars of its kind anywhere in the North Atlantic, and it is forever on the move. Built entirely of loose sand and held together only by the roots of marram grass, the island carries no trees at all; the wind reshapes its dunes from one year to the next, and its very outline shifts as the tides gnaw at one end and rebuild the other. Pools of fresh water collect in the hollows between the dunes, and it is these that allow animals to survive so far from the mainland.