The Big Race: Bob Hamilton gets into trouble when crooks cause the defeat of his father's horse in the Derby, and it is reported he is in with the crooks. The old man disowns him and his sweetheart, Patricia , breaks their engagement. So Bob and "Skipper", the also-suspected trainer, head for the western tracks, taking with them the horse Hamilton Senior forced them to buy, determined to make good and prove they are on the level.