So the "Borgia Pearl" with a provenance steeped in blood and death is stolen from a museum after "Holmes" (Basil Rathbone), rather pompously, disables the state-of-the-art electric security system and so he and "Watson" (Nigel Bruce) have to try and get it back again. This time he comes up against a formidable protagonist in "Giles Conover" (Miles Mander) and his brutal henchman "the Hoxton Creeper". This is a tense, and at times quite menacing cat-and-mouse movie based on Conan-Doyle's "Six Napoleons" that keeps your attention throughout with the stars rarely better......