The Scotland Yard man glanced towards where the Herr Doktor stood, aloof and a little disconsolate, listening abstractedly to an argument Ernest Robotham had started with Pedder and Thornley about conditions in the South African diamond industry. Clearly, the savant’s artistic soul was less stirred by the jewellery, even the Abdul Hamid emeralds, than by the jade; and Chinese art seemed to be his only talking subject. At any rate, he was silent now, an awkward scarecrow figure, lost in thought, meditating, as Dene surmised, upon some aspect of his special hobby. Scarcely an advertisement for German manly beauty, the Herr Doktor, with his eyes blank behind his thick lenses as they caught the light, his bony nose, his bulging cheeks and his rabbit mouth, the upper lip puckered up under the r
