I greatly enjoy the story and love the movie, in part because I think Andrews is an underappreciated actor. He's accused of being a stone-face, but I think that was a conscious choice and he expresses emotions in other ways -- his silence and pauses as though for thought while assessing a situation, his side-eye glances, his posture, his infrequent smiles all provide clues to his character's reactions, and these change with the character. Holden is initially a charming disbeliever, but he assesses his opponent and as a scientist seeing what works, he uses it to his advantage.
MacGinnes is excellent as Karswell. He wants the power the magic confers but seems wary of using it, perhaps doesn't care for killing. He gives dimension to a character that could easily have slipped into cardboard villain.
The monster is okay , but isn't really needed. Tourneur wanted to go more psychological in the tradition of Cat People, maintain the mystery of whether it was mostly psychological or supernatural. The producers were not sympathetic. Either way, the movie is really powerful and effective. If the producers had stayed out of it, audiences would have gone home seeing what they wanted to see, either "Oh, that crazy Karswell, driven insane and given a heart attack by his own delusions, and darned clever of Holden to realize it" or "That's what you get for messing with magic. You can't call on those powers without paying a price, and how clever of Holden to use his power against him."
Oh, and I forgot to add, thanks for sharing Extollager. Interesting article.
Randy M.