Despite this, Doctor X still manages to boil a wonderfully torrid pot of horror elements a cannibal killer; a gloomy cliffside Long Island mansion with sinister retainers; a lineup of suspicious scientists one with a missing arm conducting a study on cannibalism, another whose companion vanished under mysterious circumstances in the South Seas, and a wheelchair-ridden one who can rise to his feet under moments of hysteria; and a wonderfully lunatic scheme by Lionel Atwill to re-enact the murder with the scientists chained to their seats and wired to a giant device that will measure the buried psychological triggers that drives one of them to become a killer where their invigorated heart rate will cause a blood-like substance to rise up through ten-foot tall tubes (sort of an extraordinarily OTT lie detector). The re-enactment with low-lit closeups on the parties faces, the thrill of seeing such an extravagant pulp super-science device in action and a surprise twist wherein the murderer attacks during the re-enactment is superb. The climactic twist revelation of the killers identity where we see him attaching a hand made of artificial flesh to himself and smearing his whole head with clay is great. The only downside of the film is the inane comic relief with the practical-joking reporter character played by Lee Tracey.
Doctor X introduced the great Lionel Atwill to the world and made him a genre star up until his death in 1946. Atwill was usually cast as a mad scientist or deranged killer in the likes of Murders in the Zoo (1933), Mystery of the Wax Museum (1933), The Vampire Bat (1933), Man Made Monster (1941), The Strange Case of Doctor Rx (1942), The Mad Doctor of Market Street (1942), and of course his unforgettable role as the wooden-armed police inspector in Son of Frankenstein (1939). In Doctor X, Atwill cuts a wonderfully cool and authoritative presence. In fact, it is of some surprise in light of Atwills later career that, despite the film naming itself after his character, he does not turn out to be the killer.
The Return of Dr X (1939) was a loose sequel and is a routine mad scientist effort whose only distinction is in seeing Humphrey Bogart play a vampire.
Michael Curtiz made several other ventures into horror with a lost version of Alraune (1918) in his native Hungary and the Hollywood films The Mad Genius (1931), Mystery of the Wax Museum (1933) and The Walking Dead (1936). He is best known for Hollywood classics such as Captain Blood (1935), The Adventures of Robin Hood (1938) and Casablanca (1942).