When Grace Maclean and her beloved horse, Pilgrim, are hit by a truck one snow-covered morning, their destinies become inextricably bound to one another. Though both manage to survive the tragedy, the impact on their lives is devastating; both horse and girl are traumatised and profoundly changed. Beside herself with worry, Grace's mother, Annie Macean, hears about a man called Tom Brooker, a 'whisperer' said to possess the gift of healing troubled horses. He is her last hope and she decides to abandon her life in upstate New York, setting off across the continent with Grace and Pilgrim to find him. This journey, under the sweeping Montana sky, will change all their lives for ever . . .