"Not in his arm, you can look and satisfy yourself on that point. It is just possible that he made an injection through his clothes. It requires a more careful investigation than I can make to-night before I can give a decided opinion." "Quite so, but you do not mind my looking at the body rather closely? A little thing so often tells a big story, and the little things are sometimes difficult to find once the body has been moved." The doctor watched Quarles's close investigation with some amusement. The shirt front came in for a lot of attention, and the collar was examined right round to the back of the neck. It was a long time before Quarles stood erect and put the lens in his pocket. I got the impression that he had prolonged the investigation for the purpose of impressing the doctor. "It would be virulent poison which would kill a man so quickly and while he sat in his chair," Quarles said reflectively. "It would, indeed," the doctor returned. "You have formed no idea what the poison was?" "Not yet." "No hypodermic syringe has been found, I suppose?" said Quarles, turning to me. "No." "You see, doctor," he went on, "if the glasses there show no evidence of poison, and nothing has been moved, and you decide that poison was the cause of death, one might jump to the conclusion that it had been self-administered with a syringe; that is why I ask about a syringe." "There are such things as tablets," said the doctor, "or the poison may have been in the food he has eaten to-night." "Exactly," Quarles snapped irritably. The doctor smiled; he had certainly scored a point and was evidently pleased. "Besides, Professor, you are a little previous with your questions. This isn't the inquest, you know; we haven't got through the post-mortem yet." "I generally form an opinion before the inquest," said Quarles as he looked at each glass in turn and stirred the contents of the ash-tray with a match. "You must often make mistakes," remarked the doctor. "I propose having the body moved to the bedroom; there is nothing else you would like to look at before I do so?" "Thanks, doctor, nothing," said Quarles with a smile which showed that he had recovered his lost temper. After the removal of the body the doctor departed, fully convinced, I believe, that the professor was a much overrated person. "Well, Wigan, shall I tell you what the result of the post-mortem is likely to be?" said Quarles. "If you can. Remember you have not heard what I have to say yet." "No sign of poison will be found. No sign of violence will be discovered anywhere upon the body. Sudden heart failure--that will be apparent. The cause obscure. Organs seemingly healthy; no discernible disease. Muscular failure. Death from natural causes. A case interesting to the medical world, perhaps, but with no suggestion of foul play about it. Now let me have your tale." "But surely you--" "I assure you I have formed no definite theory yet. How can I until I have your story!"