Herbert I. Leeds directs Peter Lorre in this episode of the Mr. Moto series. Diamond smugglers in Puerto Rico murder a lead investigator; this forces the U.S. Government to call upon super sleuth Kentaro Moto(Lorre)to further investigate and break up the suspected criminal ring. As always when summoned, Moto's powers of reason prove flawless when dealing with dim-bulb hoodlums. With martial arts and mental prowess, the unassuming and mild mannered Mr. Moto is victorious in meeting the challenge. Deadpan humor is not lost in the crime and drama. The supporting cast features: Jean Hersholt, Richard Lane, Amanda Duff, Leon Ames, Paul Harvey and Warren Hymer, as Twister McGurk.

Now I realize that the Mr. Moto features were B pictures from 20th Century Fox and I have a low bar set for them accordingly, but you would think that a film set in Puerto Rico would have at least one person of Latino background as a character. Even a small scene where Peter Lorre goes to a library to do research the librarian could have been a librarian from Kankakee, Illinois. Darryl F. Zanuck should have been more alert here.With that the film does sink to below average in ratings. As for the plot itself, Mr. Moto On Danger Island finds the intrepid Japanese sleuth hired by a consortium of diamond merchants to put a stop as to his smuggling the gems from Puerto Rico. It's important enough so that the territorial governor of Puerto Rico, Paul Harvey is in on it and is giving him full cooperation. Not that it does Harvey much good, because Harvey winds up a homicide victim and Colonel Richard Lane of the army who had been investigating the situation previously winds up with the blame and the suspicion of being the man in charge of the smuggling.Such folks as Robert Lowery, Leon Ames, Douglass Dumbrille and Jean Hersholt are in the cast, any one of them a likely villain. And for comic relief the intellectually challenged Warren Hymer is along as a professional wrestler who strikes up the acquaintance of Peter Lorre while on the boat bound for Puerto Rico and attaches himself to Lorre.Fans of the series will like this, but I fear few others.

Not one of the brighter entries in the wildly uneven Peter Lorre-Sol Wurtzel Moto series, this one sets our hero on the trail of the obligatory jewel smugglers in glamorous, exotic PUERTO RICO, where he encounters a snippy library clerk and a tippy rowboat among other perils.

This is one of the later Moto pictures and not as good as the earlier ones. Peter Lorre is his usual great self. And, there is a great nostalgic sense of the time and setting. But it doesn't have as much life as the previous entries in the series. It is still worth seeing. Just don't expect to see Moto at his best. It is better than "Mr. Moto's Gamble" and far better than the 60's attempt at reviving the character, "The Return of Mr. Moto". This was based on the novel, "Murder in Trinidad" which did not feature Moto and was filmed before and since. For this film the locale was changed to Puerto Rico. At one time this was slated to be filmed as a Charlie Chan film, "Charlie Chan in Trinidad".