Paras is a spirited racehorse at a racetrack west of Paris. At dusk, one afternoon she pushes open the door of her stall--she's a curious filly--and, after traveling through the night, arrives by chance in the City of Light. She's dazzled, and often mystified, by the sights, sounds and smells around her, but she isn't afraid. Soon she meets an elegant dog, a German shorthair pointer named Frida, who knows how to get by without attracting the attention of suspicious Parisians. Paras and Frida coexist for a time in the city's lush green spaces, nourished by Frida's strategic trips to the bakery and the butchershop. They keep company with two irrepressible ducks, and an opinionated raven. But then Paras meets a human boy, Etienne, and discovers a new, otherworldly part of Paris: the secluded, ivy-walled house where the boy and his nearly-one-hundred-year-old great grandmother live, quietly and unto themselves. As the cold weather and Christmas near, the unlikeliest of friendships bloom among humans and animals alike. But how long can a runaway horse live undiscovered in Paris? And how long can a boy keep her hidden, and all his own?