Ethan Lyon’s review published on Letterboxd:
1st Roy William Neill
Jumping back on the Research Train, I find myself in the company of Mr. William Henry Pratt again. Out of his usual makeup that Universal so loved to slather him in, this little Columbia picture gives Karloff an opportunity to play a double role, that of twin aristocrats in a Mittle-European village, something he does very well. As with many a film about twins, one is all evil, the other decent. But it reverses the usual association of 'disabled=insane', by having the good twin, Anton, be the disabled one, though his disability is limited to a withered hand that Karloff places on his chest. The film therefore has an interesting subtext about the performance of disability. To maintain his disguise, the evil brother must assume the same disabled stance as his good brother, harking back to the characters of Lon Chaney, in particular his dual role in The Blackbird. The film is less a horror and more a gothic thriller, but the monstrous figure of the serial killer aristocrat is still a compelling character, almost a Bluebeard figure.
The Gothic nature of the film is evident not only in this element of doubling, but also in the quasi-European location and the visual stylings. The village and castle have the vaulted ceilings and prominent visual details associated with the movement, making the film a treat for the eyes. The other players, especially the other male leads, are good matches for Karloff, though the love story is a little drippy as ever. We also don't see enough of the titular room itself, which is a shame, because who doesn't love a good torture chamber?
Ultimately, the film isn't the best of Karloff's non-Universal star productions; that, for me, is The Walking Dead from a year later, which is a masterpiece. However, it deserves far more attention than it has been given.