As the new witness, a small, dry, eminently professional-looking man, stepped briskly up to the table, I stole a quick, rather furtive glance at my companions and saw my own alarm plainly reflected in their faces and bearing. Barbara, on my left hand, sat up stiffly, rigid as a statue, her face pale and set, but quite composed, her eyes fixed on the man who was about to be sworn. Madeline, on my right, was ghastly. But she, too, was still and quiet, sitting with her hands tightly clasped, as if to restrain or conceal their trembling, and her eyes bent on the floor. As to Wallingford, who sat on the other side of Barbara, I could not see his face, but by his foot, which I could see and hear, tapping quickly on the floor as if he were working a spinning-wheel, and his incessantly moving hands, I judged that his nerves were at full tension.

The new witness deposed that his name was Walter Randall, that he was a Bachelor of Medicine and police surgeon of the district and that he had made a careful examination of the body of deceased and that, with Dr. Barnes, he had made an analysis of certain parts of that body.

“To anticipate a little,” said the coroner, “did you arrive at an opinion as to the cause of death?”

“Yes. From the post mortem examination and the analysis taken together, I came to the conclusion that deceased died from the effects of arsenic poisoning.”

“Have you any doubt that arsenic poisoning was really the cause of the deceased’s death?”

“No, I have no doubt whatever.”

The reply, uttered with quiet decision, elicited a low murmur from the jury and the few spectators, amidst which I heard Madeline gasp in a choking whisper, “Oh! God!” and even Barbara was moved to a low cry of horror. But I did not dare to look at either of them. As for me, the blow had fallen already. Sir Robert’s evidence had told me all.

“You said,” the coroner resumed, “that the post mortem and the analysis, taken together, led you to this conclusion. What did you mean by that?”

“I meant that the appearance of the internal organs, taken alone, would not have been conclusive. The conditions that I found were suggestive of arsenic poisoning but might possibly have been due to disease. It was only the ascertained presence of arsenic that converted the probability into certainty.”

“You are quite sure that the conditions were not due to disease?”