Peterson returned in about five minutes, and they went upstairs together. The butler extinguished the hall light, leaving the lower floor of the house in darkness. A dim light burned on the second floor. Peterson tapped lightly on the door of a side chamber. It brought the nurse into the hall--a slender girl in the twenties, with thin features, reddish hair, and shifty gray eyes. She nodded and smiled, with a quick glance at the private secretary. “Thank you, Peterson,” Margate said quietly. “That’s all, my good fellow. You may go up to bed. I will turn out the light in this hall for you.” “Very well, sir,” bowed Peterson, evidently unsuspicious. “Thank you, sir. Good night, miss. Good night, sir.” “Good night, Peterson.” The butler turned away and vanished up the servants’ stairway. Margate took the hands of the nurse, slipping the vial into one of them, and for five minutes he remained in whispered conversation with her, giving her such instructions as served his purpose. Then he extinguished the hall light and went to his room. Half an hour passed. The silence in the crime-cursed house was unbroken. Its gloom was relieved only by a faint thread of light under the door of the chamber in which Madame Clayton was lying. Then, for the hundredth part of a second, a swift gleam appeared on the servants’ stairway. It shot downward, danced for an instant over the stairs and wall, then vanished. It appeared again in about a minute. It lingered for several seconds. A figure was vaguely discernible in the gloom back of the swiftly moving ray, a figure stealing noiselessly down the stairs--that of Peterson, the house butler. He crept down as silently as a shadow, as if he was far from being a novice in such stealthy work. He stole to the door of Madame Clayton’s chamber, crouching there in the darkness, and peered through the keyhole. He could see the form of the unconscious woman lying on the bed. He saw, too, that of the nurse bending above her, watching her intently, with an empty hypodermic syringe in her hand. “Just in time,” thought Peterson. “Too late to prevent it, but not too late to see what has been done. That may serve as well.” He stole away as he had come, but not to return to his room. He remained crouching near the top of the servants’ stairway, waiting patiently in the inky darkness, minute after minute, until a tall, old-fashioned clock in the lower hall struck one. Then a beam of light from another quarter dispelled the gloom. Margate stole out of his chamber and crept down the front stairs. The nurse stepped into the hall and waited, holding a bundle of garments under her arm. Margate returned in about three minutes in company with two men--Dunbar and Haley. Peterson sat watching them from the top of the stairs. He saw them enter the room, all three men, from which they presently emerged with a heavy burden--the senseless woman. Moving noiselessly, they bore her down the stairs and out of the house.