Based on a popular radio series, this Universal serial, produced in 13 chapters, starred two of the studio's better B-movie leads, Kent Taylor and Irene Hervey. Despite their fine work, the serial's preposterous plot -- a mad scientist assembling a League of Murdered Men to wreak havoc on the city -- proved too much even for die-hard serial fans. The League consisted of criminals who were injected with a death-stimulating drug and declared officially dead, only to rise from their graves fortified by Professor Mortis' reviving drug. The gangbusters of the title consisted of the mustachioed Mr. Taylor, his assistant Robert Armstrong and girlfriend Irene Hervey. The latter played a news photographer and mostly got in the way of what little action the serial offered. The leading villain was played by Ralph Morgan, brother of MGM stalwart Frank Morgan, an always watchable character actor who nevertheless often seemed to be called in whenever a studio failed to engage Boris Karloff or Lionel Atwill. Morgan had very little to work with this time around; considering Universal's proud heritage, the professor's scientific lab looked surprisingly mediocre.
by Hans J. Wollstein synopsis