"No, not very. Sometimes she has missed her last train and has stopped the night with the Penn-Pagets or the Hennikers. It is difficult, she says, to go to supper after the theatre and catch the last train. It leaves Charing Cross so early." Again there seemed a distinct inclination on her part to shield her sister. "The whole thing is a most profound mystery," she went on. "I must have slept quite lightly, for I heard the church clock strike each quarter until one o'clock, yet not an unusual sound reached me. Neither did nurse hear anything." Nurse Kate was an excellent woman whom I had known at Guy's through several years. Both Sir Bernard and myself had every confidence in her, and she had been the invalid's attendant for the past two years. "It certainly is a mystery--one which we must leave to the police to investigate. In the meantime, however, we must send Short to Redcliffe Square to find Mary. He must not tell her the truth, but merely say that her husband is much worse. To tell her of the tragedy at once would probably prove too great a blow." "She ought never to have gone to town and left him," declared my well-beloved in sudden condemnation of her sister's conduct. "She will never forgive herself." "Regrets will not bring the poor fellow to life again," I said with a sigh. "We must act, and act promptly, in order to discover the identity of the murderer and the motive of the crime. That there is a motive is certain; yet it is indeed strange that anyone should actually kill a man suffering from a disease which, in a few months at most, must prove fatal. The motive was therefore his immediate decease, and that fact will probably greatly assist the police in their investigations." "But who could have killed him?" "Ah! that's the mystery. If, as you believe, the house was found to be still secured when the alarm was raised, then it would appear that someone who slept beneath this roof was guilty." "Oh! Impossible! Remember there are only myself and the servants. You surely don't suspect either of them?" "I have no suspicion of anyone at present," I answered. "Let the police search the place, and they may discover something which will furnish them with a clue." I noticed some telegraph-forms in the stationery rack on a small writing-table, and taking one scribbled a couple of lines to Sir Bernard, at Hove, informing him of the mysterious affair. This I folded and placed in my pocket in readiness for the re-opening of the telegraph office at eight o'clock. Shortly afterwards we heard the wheels of the cab outside, and a few minutes later were joined by a police inspector in uniform and an officer in plain clothes. In a few brief sentences I explained to them the tragic circumstances, and then led them upstairs to the dead man's room.