Terrible twist at the end...

Sometimes, the people who put together these whodunit pictures are so set on getting one over on the audience that they come up with the worst possible culprits for the murders. In films like The Maltese Falcon and House on Haunted Hill (which William Castle also directed), it was a logical and enjoyable outcome for the woman seeking help to be the murderer trying to divert attention away from herself. In this movie, it was a film-ruining twist. (Granted, it wasn't exactly Citizen Kane to begin with.) They even gave us the vampish cousin so that we would suspect her of being a femme fatale. Instead, it's her hapless ingenue cousin who is wondering around stabbing, shooting, and strangling people. It's not that they outsmarted the audience, it's that nobody expected the filmmakers to do something as stupid as have the fairy tale princess as the killer.

The clock chase was a fun scene, but the film just couldn't recover from its "shocking" twist.