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.
Ralph Byrd
Dick Tracy
Kay Hughes
Gwen Andrews
Smiley Burnette
Mike McGurk
Lee Van Atta
Junior
John Picorri
Moloch
Carleton Young
Gordon Tracy, after
Fred Hamilton
Steve Lockwood
Francis X. Bushman
Chief Clive Anderson
