Just two years before his star-making turn in The Maltese Falcon, Humphrey Bogart made his sole foray into science fiction-horror in Vincent Sherman's directorial debut, The Return of Doctor X. The film provided an unusual turning point in Bogart’s career — although he had spent his first decade in the movies largely playing gangsters, heavies, and other sundry supporting roles, this role as a blood-thirsty mad scientist would prove to be the moment he realized he needed to make a big change in order to achieve his career goals.
Based on a story in Detective Fiction Weekly by William J. Makin, the decidedly B-picture cheapie The Return of Doctor X follows reporter Walter Garrett, aka Wichita (Wayne Morris), who is investigating a series of bizarre murders in which victims are drained of their rare “Type One” blood type. His investigation takes him first to a friend Dr. Mike Rhodes (Dennis Morgan), then to hematologist Dr. Francis Flegg (John Litel), whose weird assistant Marshall Quesne (Bogart) bares a remarkable resemblance to the late Dr. Maurice Xavier, who had been executed via electric chair a few years back for murder. It's soon revealed that Quesne really is the mysterious Doctor X brought back to life, surviving on a synthetic blood made from those with the rare “Type One” blood type.
