of[60] the door itself disappeared. Across the opening into the library stood a screen, and it was not until I had pushed this somewhat aside that I was able to look into that room. [60] My first glance assured me it was empty. Stark and bare of any occupant, the high-backed chairs loomed in the funereal gloom, while on the table, toward which I inadvertently glanced, stood a decanter with a solitary wineglass at its side. Instantly I remembered what had been told me concerning that glass, and stepping forward, I took it up and looked at it. Immediately I heard, or thought I heard, an exclamation uttered somewhere near me. But upon glancing up and down the room and perceiving no one, I concluded I was mistaken, and deliberately proceeded to examine the wineglass and assure myself that no wine had as yet been poured upon the powder I found in it. Satisfied at last that Mr. Benson had not yet taken his usual evening potion, I put the glass back and withdrew again to my retreat. I do not think another minute could have elapsed, before I heard a step in the room behind me. A door leading into an adjoining apartment[61] had opened and Mr. Benson had come in. He passed immediately to the table, poured out the wine upon the powder, and drank it off without a moment's hesitation. I heard him sigh as he put the glass down. [61] With a turn of my hand I slipped off both domino and mask, and prepared to announce my presence by tapping on the lintel of the door beside which I stood. But a sudden change in Mr. Benson's lofty figure startled me. He was swaying, and the arms which had fallen to his side were moving with a convulsive action that greatly alarmed me. But almost instantly he recovered himself, and paced with a steady step toward the hall door, which at that moment resounded with a short loud knock. "Who is there?" he asked, with every appearance of his usual sternness. "Hartley," was the reply. "Are you alone?" the old gentleman again queried, making a move as if to unlock the door. "Carrie is with me; no one else," came in smothered accents from without.