Ah, there's nothing like a good old-fashioned creepy & atmospheric horror tale from the early nineteen-thirties starring the almighty Boris Karloff! Be forewarned, however, that this "Behind the Mask" is not really a horror movie and that Karloff in fact only plays a supportive character – albeit quite a menacing one. Does that mean that the film isn't worth checking out? Nope, not at all, because "Behind the Mask" definitely does contain quite a few sinister twists and details in its overall very ambitious and compelling crime/mystery screenplay. A whole bunch of elite federal agents are trying to unravel a large-scaled drug smuggling network led by the nefarious Mr. X. Special agent Jack Hart takes the identity of small thug Quinn and goes undercover in a state prison where he meets Jim Henderson (Karloff); one of Mr. X's principal henchmen. The organization of Mr. X is most certainly evil, as the criminal mastermind also runs an unorthodox clinic where the patients are murdered and their coffins stuffed with narcotics. The script from the hand of Jo Swerling – also the writer of Hitchcock's "Lifeboat" – superficially seems extremely ambitious, but rather many elements are nevertheless tacky (like the forced love-story between the secret agent and one of the minions' daughter) and/or predictable (for example the identity of Mr. X is not really that secretive). Top-billed stars Boris Karloff and Jack Holt are decent enough, but the show is stolen by Edward Van Sloan in a fiendish double role, and by Bertha Mann! She depicts a creepy maid who's strategically put in the house of Dr. X's unreliable collaborators. She closely observes everyone in the house and reports to her employer via a radio installation in her room.

1932's "Behind the Mask" was the earliest Columbia title included in the hugely successful SON OF SHOCK television package of the late 1950s, reteaming Boris Karloff and Edward Van Sloan following the just-completed "Frankenstein" (shooting wrapped Nov 21 1931). Headlining is the studio's top workhorse, Jack Holt (father of Tim), playing an undercover FBI agent posing as a convict, pumping information from Jim Henderson (Karloff), part of the dope smuggling ring run by a mysterious 'Mr. X.' The somewhat dim Henderson hardly taxes Boris, who virtually disappears at the midway point (we later learn of his offscreen capture); the real revelation is seeing Edward Van Sloan in dual roles- he looks like himself in two scenes as Dr. Alec Munsell, involved in the FBI investigation, but is unrecognizable in heavy beard and glasses as Dr. August Steiner, chewing the scenery with great relish. It's a juicy, scene stealing villain, sounding very much like an evil Van Helsing, able to lawfully dispose of enemies through surgery on the operating table, rather than wielding a knife in the street, which would only attract attention. Lovely Constance Cummings finishes her third film opposite Karloff, following "The Criminal Code" and "The Guilty Generation," while Thomas Jackson, shortly after his successful pursuit of Edward G. Robinson's "Little Caesar," surprisingly comes to a bad end. Jack Holt went on to work with Bela Lugosi in a later Columbia, 1935's "The Best Man Wins" (and with John Carradine in 1942's MGM "Northwest Rangers"). Many viewers, particularly Karloff fans, grouse that it's not really a horror film, but there's certainly enough horrific touches to qualify for SON OF SHOCK, a solid pre-code melding of crime and chills. "Behind the Mask" made one appearance on Pittsburgh's Chiller Theater, July 8 1967 (followed by 1961's Mexican "Bring Me The Vampire").

Jack Holt escapes from prison and follow the advice of his friend Boris Karloff to go see a certain man if he wants to remain free and make lots of money. Holt does so and soon finds himself working for a mysterious Mr X, who is running a large criminal operation. Holt however is no cook, he is instead a federal agent seeking to break a drug ring.Made prior to the release of Frankenstein this is a film with Boris Karloff in one of his henchmen supporting roles. He's good but a bit over active. The real star here is Jack Holt who was a big star in the silent days and who's career slowly faded once sound came in. I've always liked Holt and felt he was under appreciated by most people who know who he was (The problem is that most people have no idea at all who he was). Holt here is a rugged leading man and a nice man of action. He is in short the perfect hero.The film itself is quite good. Going from big house, to country house to doctors office, this is a thriller that keeps you guessing and keeps you interested. Its nice to see a movie that isn't so formulaic that you can connect the dots and know who is doing what before you're told. The action when it comes is well done and there is generally a good amount of suspense, especially in the final moments as it is uncertain if or how out hero will escape the villains clutches.Worth searching out and perfect for a nice double or triple feature on a dark and stormy night.

This film was made during the same period as "The Criminal Code" by the same studio. It also used some of the same sets and film footage. During this period,"Frankenstein" was released and Columbia decided to play up Karloff's name and the picture's horror aspects in the advertising. But technically, it is not a horror film. It is exploited as another horror picture, this doesn't horrify sufficiently to class with preceding baby-scarers. The scare stuff seems tossed in regardless of where it fits, but it gets results because KARLOFF's threatening pan makes him a natural for his part.