Alan Ladd and his son David star in this heartwarming tale as father and son John and David Chandler. David is mute, having lost his ability to speak after witnessing the death of his mother atthe hands of the Union Army during the Civil War. Now David and his father travel the country looking for a doctor the restore David's speech.
While stopping off in an Illinois town, two crooked sheep herders attempt to steal the Chandler's dog. John tries to stop them and gets knocked unconscious in a fist-fight with the thieves. The sheep herders lie to the police about the fight and get John arrested. The town spinster (Olivia DeHavilland) takes pity on the Chandlers, namely the boy, and pays their fine in exchange for help on the large ranch that she is running alone.
One day the town doctor comes to the ranch to tell John about an experimental cure that might help David. But the doctor is in Minnesota and the treatment is quite costly. Feeling he has no choice, John sells his one possession - his dog - to a breeder who had expressed interest in the animal.
The treatment is a failure, and Chandler finds that the dog has been sold to the sheep herders who tried to steal the dog from him monthe earlier. Now it's up to Chandler to get the dog back.