Fifth in the Noirish Whistler film series (and the third Directed by William Castle) is a so-so effort despite a decent enough premise. A kindly old shopkeeper (Paul E. Burns) is looking for a young girl (Pamela Blake) who disappeared suddenly after a family tragedy seven years before. He's been holding some valuables for her. The shopkeeper hires a shady Private Investigator (Richard Dix) to find the young girl. Soon enough, a Model (Helen Mowry), a street thug (Mike Mazurki), a hotel manager (Regis Toomey) and the cops are on the case.
At barely an hour, Eric Taylor's script never fleshes out the characters. It's purely a plot driven vehicle. Unfortunately, the P.I. is such a dreary lunkhead of a character that even the twists in the tale don't land. I like Dix in a number of movies, but he isn't able to lift the part. Castle's Direction has a few minor touches and Cinematographer Philip Tannura does a decent job under the circumstances.
MYSTERIOUS INTRUDER, with it's P.I. focused story may more claim to being Noir than some of the other Whistler films (I do love that mysterious shadowy figure), but, it's still more of a crime melodrama - and, a second rate one at that.