Disillusioned by the Vietnam war and troubled by their own past, Kate and Andy leave New York City for a remote Nova Scotia fishing village in search of a simpler life. Living in Andy's boyhood summer home, they discover the old house is haunted by its original owner, Basil Tannard, who decades earlier was saved by a seal from an accident at sea. Because no one in the village believed Basil and thought he'd gone mad, Basil drowned himself. Yet he remains a ghost in the house, a soothsayer prompting Kate to believe in the unimaginable.

As Kate and Andy settle into the barren, Atlantic community and start a bookstore and begin to raise a family, they discover the problems of their own past are mirrored in the unrest of the locals who are grappling with change as modern technology threatens their traditional fishing livelihood. In their shared sense of place, Kate and Andy's lives become inextricably linked with the fate of Ivan, Will and Lena, and a love triangle, a tragic accident, and alcoholism capsize their future.

Shoal water is a treacherous place to be. Not in deep water, and not on land, it is a place in between, full of unexpected hazards, of submerged sandbars, diffracted waves, and counter currents. The story follows Kate's passage out of dependence into self-possession. It is a compelling story of navigating dangerous waters and gaining the power to redeem loss and find forgiveness and belief in the unimaginable.