For a single moment only I hesitated. But one thought was in my mind, that of Muriel. At all costs I felt that I must discover her, for her disappearance had driven me to distraction. Never before had I known what it really was to love, or the blankness that falls upon a man when the woman he adores has suddenly gone out of his life. I may have been foolish, nay, I knew I was; nevertheless, in the sudden helplessness that was upon me, I turned and answered—

“I am ready to do as you wish.”

Next instant I held my breath, and the perspiration broke forth upon my brow when I realised that my great love for Muriel had led me into an abyss of evil. Heedless of the dire consequences which must follow, I had flung myself into the toils of this mysterious woman whom I held in fear; a woman whose very touch was sacrilegious, and who was more fiendish than human in her delights and hates.

“Then it is agreed,” she said in that strange voice which had several times impressed me so. “Henceforth you are mine, to do my bidding. Recollect that passive obedience is absolutely essential. If I command you will obey passively, without seeking to inquire the reason, without heed of the difference between good and evil. Do you agree to such conditions?” she inquired in deep earnestness.

“Yes,” I responded, my mouth dry and parched. This speech of hers convinced me that she was possessed of some superhuman power which was as subtle as it was mysterious.

“Then having entered into the compact with me, first seek not to discover who or what I am. Secondly, say no word to my lover of the things you have seen or of your suspicions regarding me; and thirdly, rest confident that what I have told you regarding your friend Morgan’s suicide is the absolute truth. Seek not to argue,” she went on, noticing my intention to interrupt; “remain in patience.”

“But where shall I discover Muriel?”

She hesitated in thought.

“You wish to see her to-night—eh?” she inquired. Then, after a pause, she added: “Well, to-night if you go to Aldersgate Street Station, and remain in the booking-office, you will meet her there at nine o’clock.”

“How do you know her movements so intimately?”