The Calvary find Rusty and Rin Tin Tin following an Indian raid.
After falsely sounding the raid alarm several time, no one believes him when a real crime occurs.
When a trapper's wife dies, his son comes to the fort. However, the trapper's son does not get along well with Rusty.
After Rifle River gets clogged by a dam, the cavalry, with Rusty and Rin Tin Tin in tow, head out to blow it up.
Rusty is attacked by a mountain lion.
Rusty believes that the new teacher is really a criminal.
Susan convinces Rusty to leave the fort. While out, the two see an Indian uprising.
Lt. Masters is forced out of the Army after he refuses hunt down a gang of horse smugglers.
A crazy man is found on the desert and won't stop talking about buried treasure.
A new recruit has a hard time adjusting to army life at the fort.
Rusty becomes a match maker in order to create a family he can live with so that he will not be sent away.
Rusty and Rin Tin Tin try to help a medicine man and his daughter who are on the run from a band of outlaws.
When Jack Rockwell is killed men who were trying to steal his mining claim, the outlaws are unaware the papers to the claim are hidden in his daughter's shoe.
Rin Tin Tin is attacked by a mountain lion.