On returning to the Silbury Hotel. Gerald sat down to think over the important conversation with Rebb. To all appearances the master was as innocent as the man. Nevertheless, according to the Major, Geary had been to the Pixy's House on the fatal night, in spite of his denial. On the face of it, the negro had no reason to kill Bellaria, and Rebb had sworn that the murder was neither committed nor prompted by him. If this were so, it appeared strange that Rebb should have found Geary, not only in the grounds of the Pixy's House, but in the mansion itself, when he arrived. Seeing that Geary was thus first in the field, it was not improbable that he had caught a glimpse of the assassin. Whether he had, and had told his master, it was of course impossible to say. But Haskins determined to have another interview with the landlord of the Devon Maid, and force him to disclose the whole truth, which he assuredly had not told in his wife's presence. One important thing Gerald had learned from Rebb, and that was the truth of his surmise regarding Charity. She was--as he had always supposed--the twin sister of Mavis, and Haskins congratulated himself on guessing this before Rebb had spoken out. Still, it was just as well that rage had made the Major thus candid, and the matter was put beyond all doubt. Haskins was pleased also by the discovery, as, guided by him, Mavis would be quite willing to divide the income, and then Lady Euphemia would not be angry at Tod's runaway marriage. So far everything was right. But the mystery of the crime had still to be solved. Until it was, Mavis must continue, not only to be an outcast and a fugitive from justice, but must remain unable to claim her rights as Julian Durham's heiress. Apparently Geary and Rebb and Signor Venosta, as an emissary of the Tána Society, were all innocent. If so, who was the guilty person? Gerald wondered, if the letter to which Mavis had referred could be found, as he firmly believed that it would afford a clue to the identity of the criminal. In his own mind he constructed the manner in which the crime had been committed. Bellaria had received this mysterious letter, which for some reason overcame her fears sufficiently to make her venture out at night. To meet the writer of the letter she had opened the gates, and then had been stabbed by her own knife--Geary's weapon--which had been wrested from her in a hand-to-hand struggle. The wonder was that the struggle had not attracted attention. As it was, Rebb swore that he had heard only one scream, and that might have been uttered by Mavis when she found the dead body of the nurse. Bellaria therefore was in all probability slain unawares.