Dick Tracy's foe for this serial is the crime boss and Masked Mystery Villain The Spider/The Lame One and his Spider Ring. In the process of various crimes, including using his Flying wing and sound weapon to destroy the Bay Bridge in San Francisco and stealing an experimental "Speed Plane", the Spider captures Dick Tracy's brother, Gordon. The Spider's minion, Dr. Moloch, performs a brain operation on Gordon Tracy to turn him evil, making him secretly part of the Spider Ring and so turning brother against brother.

Jim Hanvey is a genial but top-notch detective who has retired to his country home. An insurance company hires him to find a missing emerald so they won't have to pay out the $100,000 for which the jewel is insured. It doesn't take him long to find the emerald, but he discovers that finding it was the easy part; the difficult part is getting it back to its rightful owner, and he winds up involved in a murder in which an innocent man is framed.

Questioned as a murder suspect, solid (but drunk) citizen Al Willis attacks his police questioners, is beaten, and swears vengeance against them. Next night, Lieut. Parks is murdered; Willis is the only suspect in the eyes of tough Chief Conroy, who pursues him doggedly despite lack of evidence. The obsessed Conroy is dismissed from the force, but continues to harass Willis, who flees to a sleazy town on the Mexican border. Of course, Conroy follows. But which is crazy, Conroy or Willis?

A disgraced cop aims to reclaim his honor by nailing a corrupt crime boss.

A crooked real estate manipulator sells worthless land on mortgage to flood refugees, then tries to profit by reselling the land to the state, committing murder in the process, as the Three Mesquiteers work to bring him and his gang to justice.

Ellery Queen solves a mystery involving a valuable stamp.

A doctor working with the Bureau of Pure Foods and Drugs, uses radio broadcasts to expose fraudulent patent medicines.

New York City cop Phil Donlon leaves the force to join the U.S. Olympic team. When he falls for a Marine colonel's daughter he gets kicked off the team. Joining the Marines to win the Colonel's approval many adventures follow.

A District Attorney decides to go after a doctor who is targeting young women and talking them into having illegal abortions.

Although she is secretly married to a student, a young girl is forced to give up her baby rather than be thought of as an "unwed mother".