Jack Hart (Jack Holt) is an undercover agent for the U.S. Bureau of Investigation. He is posing as an inmate in prison using the name Quinn. As part of his assignment he makes friends with another inmate, Jim Henderson (Boris Karloff). Hart’s mission is to infiltrate a drug smuggling ring and Henderson is his way in. The ring is said to be run by a mysterious man known as Mr. X. Henderson is scheduled to be released from prison soon so Hart fakes escaping to be on the outside when Henderson is out.
Hart meets up with another agent, Gorman (Clarence Burton). Together they pose as an agent chasing a criminal to give Hart a cover story. Hart’s plan is to ingratiate himself into the household of Mr. Arnold (Claude King), someone who is suspected of being involved in the drug ring. As part of his cover Hart shoots himself in the arm. He is taken in by Arnold’s daughter, Julie Arnold (Constance Cummings) who dresses his wound. Hart and Julie become attracted to each other. Arnold’s servant and watchdog, Nurse Edwards (Bertha Mann) reports what is going on to Mr. X. Hart accepts the job of chauffer to Mr. Arnold to keep tabs on him.
Meanwhile Henderson is released from prison and reports to his contact, Dr. August Steiner (Edward Van Sloan). Realizing that Arnold is having second thoughts about being involved in smuggling, Steiner puts Henderson in charge of the operation. Henderson decides to give his old prison buddy Quinn/Hart a job picking up a load of drugs. Steiner sees Quinn and recognizes him as being a government agent. Henderson prepares to do away with Quinn after the shipment is delivered by leaving him stranded at sea.
Steiner owns and operates a private hospital where he disposes of those who displease Mr. X. When Arnold is demoted, he is deemed useless to the organization, and a possible threat should he acquire a conscience. Steiner has Arnold taken to the hospital on the ruse that he has appendicitis. This way he can have Arnold mysteriously die on the operating table. Wanting to get rid of all their loose ends, Steiner plans on a similar fate for Arnold’s daughter, Julie.
“Behind the Mask” was released in 1932 and was directed by John Francis Dillon. It is an American pre-code thriller.
The movie is sometimes mislabeled as part of the horror genre, mostly likely because is stars both Boris Karloff and Edward Van Sloan, but it falls more within the thriller or mystery category. It does, however, have all the ear markings of a Saturday afternoon serial packaged into one 68-minute movie. Government agents combined with a mysterious evil crime boss only known as Mr. X are part of the usual serial story. It even had some cliffhanger type moments. There are also some twists and turns that add interest to the film. It ended up being an interesting and fun little thriller.
In 1906 the U.S. created “The Bureau of Investigation” to combat crime. It was referred to as the BOI or BI. In 1935 the name of the organization was changed to the “The Federal Bureau of Investigation” or FBI for short.