A reporter claims to have seen the face of "the Fiend", a hunchbacked killer dressed in black that is terrorizing a city and a theater in particular by poisoning people by some unknown means. The Fiend naturally makes her his next target and she has to go on the run. Hooking up with a reporter she attempts to find out the killer and remain alive.
Fast moving and making almost no real sense whats so ever this movie is as artificial a mystery as you can get. Its best described as taking a 1930's mystery and stripping it of anything other than the mystery mechanism (Murderer is on the lose killing people) while throwing in cliché characters, comic relief and making any revelation either a red herring or more likely a twist out of the left field of a ball park two cities over just to keep things going.
In any real sense its a mess, however as a pure machine it works. As totally mindless mystery time killer it can entertain you. Its the type of thing where you can pretty much guess the killer the instant he appears, but you don't care and can't be sure because the film is making so many odd turns that nothing makes sense even though you're hoping it will.
I don't know if you should search it out, but if you run across it an want to see as nonsensical and stripped down mystery as you can get its worth a shot. (I just don't recommend this if you need things to make and real linear sort of sense)
