But young Dr. Mason (Pryor) and his assistant Judith (Sayers) are determined to uncover the truth behind the disappearance of the esoteric Kravaal and the details of his mysterious research.

They locate Kravaal's abandoned laboratory, and there they find the scientist completely frozen in a block of ice - but still alive!

Once thawed, Kravaal begins to tell the two about his experiments in 'frozen therapy,' an attempt to halt all kinds of human disease and discomfort by freezing the subject's body under subzero temperatures.

But Mason and Judith's academic joy turns to sheer terror when the two discover that Kravaal will stop at nothing to see his life's work completed...even if a few innocents have to die in the process.

Also known as Behind the Door, this '40s horror from Columbia is overly talky and feels a bit confined. But it does yield up another strong mad scientist role for Karloff.

Kravaal's descent into madness is a palpable one. His ruthless yearning for professional success is played sympathetically, both thanks to Karloff's controlled performance.

And careful pacing from director Grinde (1939's The Man They Could Not Hang) complements Karloff's classy turn here.