Energetic 10-year-old Jimmy Warner (Jackson Pace) is forced to say farewell to his beloved German shepherd, Rainy, when his family moves from a quiet town in Louisiana to a pet-prohibited apartment in the Big Apple. But Rainy has other ideas and soon begins an epic journey to join his master. Along the way, Rainy proves via good deeds and amazing feats (such as driving a car through Manhattan) that he’s just about the best pal a boy could have.