The Lone Defender
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.
- Genre: Action
- Studio: Mascot Pictures
- Keyword: german shepherd, movie serial, dog hero
- Cast: Rin-Tin-Tin, Walter Miller, June Marlowe, Josef Swickard, Buzz Barton, Lee Shumway