"Without mentioning names, the experts consulted in the other cases which--according to the late Gaston Max--were victims of 'The Scorpion,' do not seem to have justified their titles. I am arranging that you shall be present at the autopsy upon the body of Gaston Max. And now, permit me to ask you a question: are you acquainted with any poison which would produce the symptoms noted in the case of Sir Frank Narcombe, for instance?" Stuart shook his head slowly. "All that I know of the case," he said, "is that he was taken suddenly ill in the foyer of a West-End theatre, immediately removed to his house in Half Moon Street, and died shortly afterward. Can you give me copies of the specialists' reports and other particulars? I may then be able to form an opinion." "I will get them for you," replied the Commissioner, the exact nature of whose theory was by no means evident to Stuart. He opened a drawer. "I have here," he continued, "the piece of cardboard and the envelope left with you by the missing cab-man. Do you think there is any possibility of invisible writing?" "None," said Stuart confidently. "I have tested in three or four places as you will see by the spots, but my experiments will in no way interfere with those which no doubt your own people will want to make. I have also submitted both surfaces to a microscopic examination. I am prepared to state definitely that there is no writing upon the cardboard, and except for the number, 30, none upon the envelope." "It is only reasonable to suppose," continued the Commissioner, "that the telephone message which led Inspector Dunbar to leave your house last night was originated by that unseen intelligence against which we find ourselves pitted. In the first place, no one in London, myself and, presumably, 'The Scorpion' excepted, knew at that time that M. Gaston Max was in England or that M. Gaston Max was dead. I say, presumably 'The Scorpion' because it is fair to assume that the person whom Max pursued was responsible for his death. "Of course"--the Commissioner reached for the box of cigarettes--"were it not for the telephone message, we should be unjustified in assuming that Mlle. Dorian and this"--he laid his finger upon the piece of cardboard--"had any connection with the case of M. Max. But the message was so obviously designed to facilitate the purloining of the sealed envelope and so obviously emanated from one already aware of the murder of M. Max, that the sender is identified at once with-- 'The Scorpion.'" The Assistant Commissioner complacently lighted a fresh cigarette. "Finally," he said, "the mode of death in the case of M. Max may not have been the same as in the other cases. Therefore, Dr. Stuart"--he paused impressively--"if you fail to detect anything suspicious at the post mortem examination I propose to apply to the Home Secretary for power to exhume the body of the late Sir Frank Narcombe!"