IN WHICH A DISCOVERY IS MADE. It was past four in the morning when Aloysius Stapleton got back to his flat in Sandringham Mansions, Maida Vale. After remaining with La Planta nearly an hour, he had gone back to Cavendish Square, where he found Jessica still unconscious, her symptoms being somewhat similar to Archie’s, though her brain, while she slept, seemed to be active. Several times she had, he was told, murmured incoherently, and twice she had spoken several words. Even when he arrived there her lips kept quivering at intervals, as if she were dreaming. “How long ago did the guests leave?” he inquired of her maid. “The last few of them have not been long gone,” she answered, “not above twenty minutes.” “Do you know which were the last to go?” “I don’t, sir. I only heard them leaving. Ought she not to be put to bed now, as you don’t wish the doctor to be sent for?” “Yes, take her upstairs. She will be all right in the morning.” “I sincerely hope so. She is never taken this way--never.” The maid spoke almost reproachfully, as though Stapleton were in some way responsible for her mistress having fainted. “Send John to me,” he said to her sharply. When Mrs. Mervyn-Robertson had been carried up to her bedroom, Stapleton took the footman into the dining-room and shut the door. “Now, tell me,” he said, “who were the last to leave to-night?” The young footman described them. Yes, he admitted that among them were the two guests, the man and the woman, who had been with Jessica while she drank champagne at the sideboard, but he did not know their names. Stapleton’s brain worked rapidly while he mechanically undressed in his flat in Sandringham Mansions. There could be no doubt, in his opinion, that the hand that had drugged La Planta had also drugged Jessica. In addition, he felt convinced that whoever had done it had been among the guests at Cavendish Square that evening. But who could it have been, and with what object had he, or she, committed the despicable act? After ascertaining by telephone next morning that both Archie and Jessica had recovered and were once more in their right senses, he drove in his car first to the Albany. Archie, wrapped in an elaborate dressing-gown of Japanese corded silk, was having breakfast in his bedroom. He looked unusually pale, Stapleton thought directly he entered, and there were dark marks under his eyes. “I wish you would tell me, Louie,” Archie said, “what happened to me last night, and how I managed to come away from the Alhambra without my hat. I might have imagined I had drunk too much--had there been anything to drink.” “I can tell you nothing, because I know nothing,” Stapleton answered, and went on to explain how they had suddenly missed him from the box, and what had happened afterwards. “Who was it brought the message for Jessica, and why did you leave the box without delivering it to her?” he ended.