Tom King Jr. seeks to discover who murdered his father, a Texas Ranger; the trail leads to a network of Axis spies.

The Canadians have discovered a valuable substance called Compound X, which can cure infantile paralysis. When a country at war with Canada learns that Compound X also contains magnetic properties that could aid them in their warfare against the British, they send agents to infiltrate Canada and steal a large quantity of the substance. It's up to Sgt. King (Allan Lane) and his Mounties to track down the agents and put an end to their scheme.

Calvin Drake employs a group of low-lifes to drive away land owners along the path of a new railroad; Red Ryder opposes this strategy.

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.