It isn't a bad story or intrigue, but it hasn't been properly developed. Hitchcock could have made something up to his standard, he liked show intrigues, and this is out of the ordinary as it is entirely about freaks, and the murder intrigue must be regarded as extremely bizarre. There is not just one murder but they keep mounting, as the murderer has to cover up his crime by new crimes, as they always do, but we never learn his motive, if he had any. The real vicious character is the circus detective who is constantly on the alert for victims to blackmail, and the line of them is growing. The one attraction of the film is Tonia Bern as the lovely Rena Maroni, with whom everyone is having a relationship, she is also a freak but we never learn of what kind. Pity that so many had to be sacrificed for nothing but fishy business circumstances about a grotesque freak show, which apparently no one got anything out of. Still John Ireland tries to appear convincing when he insists that the show must go on.
Review of The Glass Tomb
