A mad doctor named Zanoff uses a drug to bring himself back from the dead after his execution in prison. Dick Tracy sets out to capture Zanoff before he can put his criminal gang back together again.

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.

The coming of the railroad to Cedar City spells the end of the stagecoach as the government gives the mail contract to the fastest means of delivery. McCord loses the stagecoach line gambling with the new buyer, but has enough hidden money to buy a ranch and some cattle. To make more money, he starts a gang to rob the railroad, express offices and steal cattle. But the railroads send out special agent Cameron to end his reign of violence.

An imprisoned gunfighter must scatter to elude the authorities. Outlaws Bob Ford and Vic Rodell are nabbed, but the governor offers them amnesty in exchange for their help in bringing Jesse and his brother Frank to justice.

Notorious outlaw Clay Anderson and gang rob the town bank and flee in separate directions. Riding hard, Clay's horse goes lame and he is forced to pull-up at a nearby farm. He soon discovers that the place belongs to local preacher Hollis Jarret, his new wife, and a son from a previous marriage. Clay, posing as a weary traveler, tries to insinuate himself into a secure hideout, but the reverend isn't fooled. He agrees to allow Clay to remain at the farm for a few days, but his motive isn't the preservation of his family's safety. Hollis reasons that, with time, patience and a lot of faith, he can convince the outlaw to turn over a new leaf. But Clay's criminal tendencies may run deeper than the preacher had imagined

Wanted outlaws have mysteriously disappeared. Ranger Captain Henley and Steve have a plan to find them. Steve becomes a wanted man by faking the killing of Henley. Not only is he now in trouble as both the Rangers and the Mexican Rurales are after him, but Smiley knows him and may expose his masquerade to the bad guys.