Jack Logan is the heir to half of a map to a hidden Indian mine. The trader and villain Jean Gregg sends his chief henchman Mack to make life difficult for Jack. Jack is aided in his quest by the heirs to the other half of the map: Helen Holt and her younger brother Billy, and by a uniformed mystery man known as "The Mystery Trooper".
Billy takes a trip to the the zoo with his wife and two sons. He is proud to show his knowledge about wild animals to his older son, who is preparing for an exam.
When a criminal named King Fu who has terrorized a city substitutes himself for a stage actor who resembles him, the staff and spectators at that night's show think the actor is giving an unusually good performance.
A truck driver "too lazy to work and too nervous to steal" gets mixed up in racketeering. Naturally his underhanded business practices make him a pillar of the community.
Katusha, a country girl, is seduced and abandoned by Prince Nekludov. Nekludov finds himself, years later, on a jury trying the same Katusha for a crime he now realizes his actions drove her to.
