The Devil Commands (1941)

No devil appears in the movie.

The Devil Commands (1941): adapted by Robert Andrews and Milton Gunzburg from the novel The Edge of Running Water by William Sloane; directed by Edward Dmytryk; starring Boris Karloff (Dr. Blair), Cy Schindell (Karl), Amanda Duff (Anne), Anne Revere (Mrs. Walters) and Richard Fiske (Richard): 

Moody, atmospheric horror film with Karloff as a Mad Scientist, or more accurately a sane scientist driven mad by his wife's death and the subsequent revelations about the afterlife as revealed by his investigations into brain function.

Frame narration from Karloff's daughter doesn't really help with suspense, but the movie as a whole is enjoyable. Karloff is more mournful and far less threatening than usual as the increasingly loopy scientist who believes that he can build a machine to communicate with the dead in general and his wife in particular. And what a machine! The final form of his 'Dead Set' really makes the whole movie worthwhile. It's Vacuum-Tube Gothic.

Other elements are perhaps a bit more rote, from the grieving daughter and her boring love interest to the wily sheriff. Karloff's hulking henchman Karl possesses a bit more pathos than most such characters, as we see the accident that 'creates' him. An unscrupulous 'fake' medium who turns out to have real psychic powers (shades of Ghost!) rounds out the major players.

Director Edward Dmytryk is better at mood and atmospherics than he is pacing -- the whole thing drags a bit, which shouldn't really happen with a 65-minute movie. Nonetheless, a grim and surprisingly downbeat movie for its time. Recommended.