A gambling ring run out of the Mogul Taxi company is intent on fixing college football games. Football star Harold "Red" Grange is a target for the gamblers, whose thugs try to eliminate Grange from playing. Grange's buddy Buddy is himself vulnerable to blackmail, since he has broken team rules by marrying. The crooks use all their wiles to keep Grange and Buddy from leading their team to victory.
A prospector is murdered by The Cactus Kid and his gang, who hope to find the murdered man's goldmine. The miner's dog, Rin-Tin-Tin, recognizes the killers, who thereafter seek to use the dog to locate the lost mine. With the help of a government agent and a young girl, Rinty saves the mine and brings the bad guys to justice.
A ship captain's beautiful daughter and a wealthy playboy who is searching for buried treasure find themselves stranded on a desert island.
