"I daresay. No cabman had any right to suspect his fare of murder. But we will question those on the rank before we go to Soho. Let us find out if Mr. Zirknitz took a cab between a quarter-past and half-past eleven." Ellis shrugged his shoulders. "As you please. But it seems to me futile to waste time in asking questions which cannot be answered." "We have yet to learn if our time is being wasted," retorted Cass, and ending the conversation for the time being, the young men left the house. By this time Cass had become quite eager to solve the mystery, and willingly placed his quick wit and indomitable perseverance at the service of his friend. He admired Ellis greatly, and there was quite a David and Jonathan feeling between the two. It annoyed Cass to think that the doctor might throw away his life on such a woman as he believed Mrs. Moxton to be; and he undertook the case in the hope of proving her unworthiness. At the present moment appearances were decidedly against her, yet in the face of such black evidence Ellis still clung to his belief in her. This instinctive feeling, based on no reasonable foundation, was so insisted upon by Ellis that his friend became quite angry. "It is the most sensible men who become the greatest fools on occasions," he said, with the rough speech of intimate friendship. "You have known this woman only three weeks, and you are absolutely ignorant of her past life save what she has chosen to tell you. The circumstantial and actual evidence points to her not only as a shady person, but as a positive criminal, yet in the face of it all you look upon her as a saint." "No, I don't. I told you so before; but I feel sure she is a good woman. I can give you no reason, but I myself am satisfied without one. As to your evidence, Harry, you know the most innocent person can be wrongly accused, can be even hanged on evidence which, false as it is, appears sufficient. There is the Lesurques case, for--" "Oh! the Courier of Lyons. I know. And I can quote you at least a dozen others. All the same, I don't believe in Mrs. Moxton." "Well, I do. For all you know she may be protecting her sister." Cass stopped short. "Has she a sister?" he asked. "I believe so. At least, in the books I told you about, Thomas Gordon had written the names of his daughters Laura and Janet Gordon. The first is, of course, Mrs. Moxton, the second name must be that of her sister." "Perhaps. But the sister may be dead, may be absent from England. In any event, I do not see how you can connect her at all with the murder."