The Mystery of Mr. X

There's a guy in between the World Wars London who's going around knocking off London bobbies with a sword cane. Henry Stephenson and Lewis Stone can't figure it out at all.

One of the murders happens at a time when cracksman Robert Montgomery has stolen a very valuable diamond and Scotland Yard links the two crimes mistakenly. And they also link upper middle class society twit Ralph Forbes to the next one.

Montgomery realizes he can't fence that valuable jewel with the heat on so he tries by subterfuge to aid Scotland Yard. Of course this tangles him up with Elizabeth Allan who is Henry Stephenson's daughter in the film and Mrs. Robert Montgomery in real life.

Robert Montgomery is poaching a bit on Ronald Colman's territory, but he does a fine job as the thief. Henry Stephenson as always is THE quintessential English gentleman and Lewis Stone is a hard and driven inspector trying to catch the maniac.

The police do make mistakes here, but the mistakes are completely understandable and really the fault of both Forbes and Montgomery who step into it themselves.

By the way you know that this picture is before the Code because it is by no means clear that Montgomery will ever give up a life of crime.