This last but one outing for Peter Lorre in the title role is a really lacklustre affair with precious little for either us, to him, to sink our teeth into. Our contemplative detective is despatched to Puerto Rico to investigate a diamond smuggling racket that cost his predecessor his life. En route he bests and befriends the nice but dim wrestler "McGurk" (Warren Hymer - whom I could have sworn was Ward Bond) and so acquires quite an useful bodyguard as his task becomes positively dangerous. Sadly, though, the infiltration and exposure elements of the story are quite weak, and the opportunities for "Moto" to use his celebrated cerebral skills are sparse. It's engaging enough to watch, though, just a shade on the predicable side.