Professor Moriarty mysteries (Michael Kurland)

"In London, 1892, a well-guarded young nobleman goes missing under distressing circumstances. The nobleman, one Baron Renfrew, is actually Prince Albert Victor, eldest grandson of Queen Victoria. He disappeared while he was visiting a house of ill repute, with bodyguards both inside and outside the building--with his inside bodyguard rendered unconscious and the trussed-up corpse of a brutally murdered young woman left behind. Hoping to find the missing...