Blair is obsessed with the study of human brain waves: tracking their individual rhythms, capturing their signature ids, and hypothesizing about the brain's potential to communicate outside the realm of conscious thought.

But then, Blair's beloved wife Helen (Warde) dies in a tragic car accident, and the grief-stricken scientist drops into the abyss of insanity.

Assisted by his cold-blooded aide Mrs. Walters (Revere) and a mute heavy named Karl (Penney), Blair is convinced he can use his research on brain waves to contact Helen from beyond the grave...even if it means he'll have to rob a few graves and kill some unsuspecting folks in order to succeed.

Another mad doctor vehicle for Karloff, this 1941 horror from Columbia is mediocre fare at best.

Decently acted, but often routine and lacking much passion, this is buoyed by the interplay between Karloff and Revere and their scenes together.

Revere's clinical demeanor as Mrs. Walters, and Karloff's effortless ability to elicit sympathy even while performing evil, propel The Devil Commands forward - all in spite of a dull supporting cast and an anti-climactic finale.

Also known as The Devil Said No.