Charlie Chan (Warner Oland) and Chief of Police Jules Joubert (Harold Huber) track down theft of metallurgic bonds and murder in Monaco. Huber has a great deal of time on screen and he plays his character with the comedy that mars his department. Supporting character actor Louise Mercier does a great job as a taxi driver whose conveyance gets the best of him and son Lee Chan's misuse of French gets him into trouble.
Early theme in movie is repeated use of number `25.' Lee points out that their hotel room is 125, he is 25 years old, this is the 25th of August, this is the Chinese Year 9325 - and therefore the number 25 will be lucky at the roulette wheel. Chan point out that Lee had borrowed $25 the week before. Later we learn that the value of the missing bonds is $25,000, one of the suspects borrows an amount equal to $25,000, and heretofore there had not been a murder in Monaco for 25 years. Poor writing fails to capitalize on this theme and the storyline sounds better in movie reviews than as portrayed on the screen.
Lots of misdirection and suspicion but in the end, Chan and the police trap (`Questions are keys to door of truth') the guilty party using knowledge that was known only to police and not the viewer. One clue might have been picked up on by an observant viewer, but the other part of the explanation at the end goes beyond what we could have known. When confronted, the guilty party makes a final error in revealing yet another fact known only to police and murderer (again not to viewer). Not one the best of the Chan series.
This is the final appearance of Oland live in a produced film - he died the following year. In this movie, as Chan, he says: `Humble presence of no more importance than one drop of rain in cloudburst.' On the contrary - although the Chan series is not high art, this viewer thinks that we are better for Oland having played the role.