I read Montague Rhodes James' original story after seeing the movie on TV. There have been [at least] 2 TV plays based on the same tale - neither did the original justice. Some of the stills, in colour, of the monster are pretty scary.but the genre, in 1957, didn't merit Technicolor. Pity they couldn't remake it today, with all our digital technology.
The atmosphere generated by master director, Jacques Tourneur is brilliant. From the subconscious invasion of creepy footsteps to the invisibly-planted smoking hoofprints that pursue hero, American psychologist John Holden; the first appearance of that hideous monster face to its shredding of its summoner, evil Julian Karswell - scary. The bit where the starry flecks come together, before the smoke announces the demon's appearance - that gave me nightmares for weeks. The music was perfectly in harmony with the action. The romantic side was played down: glamorous Peggy Cummins was the attached sleuth, but also the endangered heroine. M R James wasn't romantically inclined, though admitted occasional love-interest, and probably would have liked the movie. The last scene, with railway workers and Fuzz scratching their heads over the fuming ruins of Karswell's corpse, probably would have pleased him.