Trivia

At one point Holmes says to Watson, "If you ever see me getting too sure again, fancying myself more clever than Adrea Spedding, just whisper one word to me: pygmy." This line was inspired by the short story "The Adventure of the Yellow Face," in which Holmes tells Watson, "If it should ever strike you that I am getting a little over-confident in my powers, or giving less pains to a case than it deserves, kindly whisper 'Norbury' in my ear, and I shall be infinitely obliged to you."

Angelo Rossitto, who played the pygmy in black-face, was a diminutive character actor best known as one of the vengeance-seeking carnival acts in "Tod Browning's Freaks" (1932). He was also familiar to the denizens of Hollywood, where he operated a newsstand for three decades.

Shooting lasted from May 10-early June, 1943, released January 21, 1944 (copyright 1943) .

A follow-up, Vuelve la mujer araña (1946), has no relation to the HOLMES feature, as Gale Sondergaard plays a completely different character.

At approximately one minute, fifty five seconds into this film, a scream can be heard as one of the victims falls to his death. This scream was recorded by Boris Karloff for the 1939 "Son Of Frankenstein". In "Son ...." that scream was heard twice; once when the Monster finds his friend Ygor has been shot, then at the end of the film, when the Monster falls into the sulfur pit. That same scream will be used again in 1944 in "House Of Frankenstein" as Daniel's scream as the Monster throws him out of the laboratory window.