"Harry, what makes you think that Mrs. Moxton--" So far Ellis proceeded violently, then stopped with the conviction that he had betrayed his secret. "The cap fits, I see," remarked Cass, pointedly, and shut up in his turn. For the next few minutes there was an embarrassed silence, neither man being willing to speak, lest a word should act like a spark in a powder magazine. Ellis threw down his pipe, and, as was his fashion when annoyed, took to rapid walking in the limited space of the sitting-room. Cass eased his position on the sofa and waited developments. "Yes, it is true," said the doctor, in a loud voice, so as to drown opposition. "I am in love with Mrs. Moxton. Now, what do you say?" "Only this. It is hard enough for you to make a career without seeking for a clog which will prevent you rising in your profession." "How do you know Mrs. Moxton would prove such a clog?" "I don't know; I surmise only. I am ignorant of the lady's personality, save from what I have learnt in chance moments. You are in the like position." "I know her better than you do." "Possibly. But do you know her well enough to risk making her your wife?" "I didn't say that I intended to ask her to marry me." Cass laughed. "That is a quibble. With honourable men a declared passion is always the prelude to marriage." "But I have not declared my passion," argued Ellis, in vexed tones. "Not yet, maybe, but you will do so when the time comes." "After all, Harry, she is a charming woman." "Charming and pretty, no doubt. But is she the wife for you? Before you can answer that question, you must know her past and whitewash her present." Dr. Ellis sat down aghast. "Good heavens, Cass! Surely you don't think her guilty?" "I don't know enough about the case to say," said Cass, meditatively; "but Mrs. Moxton puzzles me, I confess. For instance, she tells lies." "Tells lies!" repeated the widow's champion, with great indignation. "Yes, and in the most unblushing manner. At the inquest she said that she took her husband's body in her arms and felt the blood flowing from the wound in his back. Now, it is my impression that she never touched the body." "How can you prove that?" "Very simply. When she came into this room she wore a plain black dress, with cuffs of white linen. Now, if she had handled the body and had touched the wound, it is only natural to suppose that those cuffs would be stained with blood. I noticed, however, that they were not." "But that is all the stronger proof that she is innocent." "Of the actual murder, maybe, Bob; but it does not prove that she is ignorant of who killed the man. She told lies about the handling of the body, as I said. It seems to me," added Cass, reflectively, "that Mrs. Moxton is shielding the assassin." "But why should she shield a murderer?"