The Littlest Horse Thieves is set in the mining country of Yorkshire in the early 20th century. The local mine is set to replace its pit ponies with machinery, and the owner decides that the best course of action is to send the animals to the slaughterhouse. Three local children hear about this and decide that the only course of action is to steal the doomed ponies from the mine. Of course, they are caught, but their action attracts the sympathy of the miners, who strike for a better fate for the ponies. Then there is an explosion, trapping a number of miners underground. What is the best way to rescue them? Although this is a Disney movie, it is a serious drama and has a grim tone to it, helped by the dark setting of the mine and the Yorkshire moors. The movie is distinguished by being the final feature film appearance of both Alastair Sim and Duncan Lamont.