In 1930s Calcutta, a beautiful racehorse brings together a group of outsiders: John Quillan, a talented trainer ostracized for his marriage; Mr Leventine, the shrewd new owner of Dark Invader; Ted Mullins, his groom, whose career has been derailed by scandal; and Mother Morag, head of an order of nuns working with the city’s poor.

Sold in disgrace and shipped to India after a disappointing first season, the horse requires gentleness and careful handling – but soon becomes the firm favourite for the famous Viceroy Cup. Then, days before the race, Dark Invader disappears. When all seems lost, Mother Morag’s sharp wits and gentle wisdom may just be their salvation. . .