A week ago Turner Classic Movies celebrated Boris Karloff's birthday by showing a marathon of his films and among them was this little seen and little talked about murder mystery. It's a slight film and really only of interest to Karloff fans and aficionados of the kind of tight, fast mysteries that the major studios would pump out by the dozens in the 1940's. Those films were built to be series with a recurring main character as the sleth (The Falcon, The Crime Doctor, Lone Wolf, etc.) in the mode of the highly successful Charlie Chan films.
THE INVISIBLE MENACE was not built to be the start of a series and for that I am glad! The only character that could possible have fit the mold as a mystery solver/crime fighter in a future film is Colonel Rogers (Cy Kendall) and the guy is a tin-plated jerk! He decides almost immediately that Karloff's character is guilty and then proceeds to spend the next fifteen minutes of the film slapping and punching him around in an attempt to get a confession! And in full view of every officer and witness on the army base where the crime took place. Dumbass!
Overall the film is a pretty solid murder mystery and, of course, Karloff is a major red herring. There is some not bad comedy, the mystery element is pretty decent and the film runs less than an hour so it certainly doesn't have time to wear out it welcome. Minor Karloff but of interest for those that are curious.