Carey Greenway (Peggy Cummins) is the niece of a farmer (Charles Coburn) who raises purebred racing horses. She has eyes for Ken (Robert Arthur), the son of rival horse rancher Rob (Lloyd Nolan), but the budding relationship between the young lovers is complicated by the tension that exists between their families. Things take an abrupt turn, though, when an untamed stallion named Thunderhead breaks onto Rob's ranch and frees his finest racing mare from captivity.