After the death of his father, a horse trainer, scientist David Palmer devotes himself to Dan Patch, a harness-racing horse. When the horse's driver takes ill, David drives Dan to a record time at a Kentucky track. When David refuses to sell the farm, his wife divorces him. With his attention now focused on his horse, David grows closer with trainer Cissy Lathrop. As they fall in love, Dan Patch tries for racing glory.