I forget if I ever posted my take here:

For what was ostensibly a B picture, The Amazing Mr. X (1948) has a lot going for it: Fabulous cinematography by John Alton, striking California coast locations including the Villa de Leon in Pacific Palisades (still standing), a neat twist at the 2/3 mark, and probably the best performance that Turhan Bey ever gave (he had fond memories of the production). On the minus side, Lynn Bari has an increasingly thankless role – her character clearly has mental problems besides being duped from two directions – and the last 10 minutes raise too many credibility questions even for a movie of this Gothic type. But overall a great watch, and justly celebrated among buffs.