"Do you believe this?" asked Ronald, savagely.

"No, I don't," replied the detective, blandly; "but we may as well look at all sides of the question. I daresay Miss Cotoner is as innocent as you or I of this crime. Still, we must lose no opportunity of getting evidence."

"Stop a moment," said Ronald, calmly; "because the name of Mrs. Verschoyle was Cotoner I do not see that Miss Cotoner is implicated--there are, no doubt, more people than one of that name in Valletta."

"Of course there are," said Foster, quietly; "but Miss Cotoner's mother's maiden name was Vassalla."

"What?"

"Yes! that was the reason of my surprise, when I heard the name last night."

"That proves nothing."

"Only that her cousin's name is also Vassalla. So it proves, pretty clearly, that Miss Cotoner is Mrs. Verschoyle's sister."

Ronald groaned; for there flashed across him Verschoyle's remark that his wife had Arab blood in her veins, and that Miss Cotoner had made the same statement at Gibraltar; so it seemed true, after all.

"Go on," he said, huskily; "what is to be done now?"