Plot
Young Danny O’Shea (Robert Gordon, billed as Bobby Gordon) dreams of a better life beyond the hardships at home. With nothing but hope in his heart and his beloved dog Rinty (Rin Tin Tin) at his side, he sets off to make his way in the world. The boy and his faithful companion stow away on a freight train headed south toward one of the great racing cities.
Their journey nearly ends in trouble when a sharp-eyed train master discovers them. But fate intervenes in the form of Virginia Calhoun (Virginia Brown Faire), a kind-hearted young woman and the sweetheart of prominent racehorse owner Bob Hammond (Carroll Nye). Thanks to her intercession, Danny avoids punishment and is offered a job in Hammond’s stables.
Danny quickly proves his worth, and when the season’s most prestigious sweepstakes draws near, he is given the incredible honor of riding Black Raider, Hammond’s prized horse. But the promise of glory is soon shadowed by treachery.
Bruce Morgan (Jim Mason, credited as James Mason), Hammond’s ruthless rival, is determined to sabotage Black Raider’s chances. In the dead of night, he sneaks into the stables intending to cripple the stallion with a curry-comb. But in the confusion, the wrong horse is injured. Caught in the act by the ever-vigilant Rinty, Morgan hurls the curry-comb wildly and throws a bucket of ammonia into the dog’s face, blinding him temporarily. Framing Rinty as a dangerous, rabid animal, Morgan claims the dog attacked the horses. Danny, fearing for his companion’s life, hides Rinty in an abandoned shack.
On the day of the great race, Morgan escalates his scheme by kidnapping Danny. With no rider for Black Raider, Hammond has no choice but to accept a last-minute replacement—one of Morgan’s own men. But Rinty, despite his injuries, escapes from the shack and tracks down his young master. He frees Danny, who locks the crooked substitute rider in a closet and races to the track.
Danny mounts Black Raider just in time, but the horse lags behind the others. Watching from a window above the track, Rinty breaks his leash and dashes to the track, running alongside his friend and hero. With Rinty at his heels, Black Raider’s spirit surges—his power and drive return. He closes the distance and, with a burst of speed, wins the race by half a length.
Morgan’s sabotage is exposed when the missing curry-comb is found in the injured horse’s stall. As justice is served, Bob and Virginia celebrate their victory. Danny, hailed as a hero, uses his share of the prize money to bring comfort and happiness to his mother—closing this heartwarming tale of courage, loyalty, and the bond between a boy and his dog.
