A slightly better than average outing for our eponymous detective (Morgan Conway) as he tries to track down the violent thug "Cueball" (Dick Wessel) who has already murdered once - with what appears to be a very thick shoelace - to acquire a valuable stash of diamonds. His brave girlfriend "Tess" (Anne Jeffreys) steps in as a broker trying lure the greedy criminal to them. It's not got any amount of suspense to it, but that doesn't matter - with Douglas Wilton as "Percival Priceless"; Ian Keith as the wonderfully named "Vitamin Flintheart" and the diamond dealer "Mr. Sparkle" - Harry…