Rusty and Rinny befriend an old man who's a Shakespearean actor. When he agrees to put on a benefit for Army widows and orphans, some unscrupulous men force him into a plot to take the ticket money.
A former soldier betrays his brother, who's on an important military assignment, and takes his place in order to divert a shipment of gold for his gang.
Mr. Tubbs is the sole witness to testify in a bank robbery case. But the accused's gang come up with a fiendish plan to keep the old man from testifying against the robber at his trial.
Cpl. Rusty turns himself in to the Apache tribe, after he mistakenly believes that he accidentally shot one of their braves during target practice. Little does he know, but the brave was actually shot by a member of the rival Comanche tribe.
When a miner's daughter gets lost in the mountains, Lt. Masters, Rusty, Rin Tin Tin, and the soldiers of Fort Apache go looking for her. They are joined by two prospectors whose sole motivation is to find The Lost Scotsman's Mine.