Elegant fun with a generous helping of suspense is the order of the day in The Mystery of Mister X, a nifty, tidy little crime thriller that's a jolly fine way to pass an hour and a half. X has many elements that will warm the hearts of dedicated mystery fans: a sophisticated gentleman burglar, a homicidal maniac, an intricate but not confusing plot, some surefire set pieces, and plenty of good old London fog. The trio if screenwriters, including original source author Philip MacDonald, keep the story trim and engaging but allow plenty of time for character details and revealing moments. Granted, the obligatory romantic angle is just that -- obligatory -- and brings about a not-too-convincing change of heart in our hero; but the rest of the film is so fine that most people will be willing to overlook this little flaw. Edgar Selwyn directs capably and with a decent amount of flair and is especially good at atmosphere, a crucial element of X's success. Even more crucial is star Robert Montgomery's totally engaging and disarming lead performance. He's irresistible from first to last and holds the film together with his effortless charm. The rest of the cast is quite good, as well, but it's Montgomery who anchors the film solidly.
by Craig Butler review