“I—I know nothing,” she declared. “Nothing except what you already know. Short knocked at my door and I dressed hastily, only to discover that the poor old gentleman was dead.”

“Was the house still locked up?”

“I believe so. The servants could, I suppose, tell that.”

“But is it not strange that Mary is still absent?” I remarked, perplexed.

“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.”