"I fancied a lot, but I saw really nothing to increase my suspicions. One thing we know—that he is concealing some person in that locked room. Now who can the person be?" "It may be some relative who has done something very wrong and is afraid of the police," suggested the girl. "Agreed. It may be. But we have discussed the matter so many times that I think we should not talk further—but act," he said. "We have proved beyond doubt that Bernard Boyne is a man of mystery. Your deaf aunt, a most worthy woman, acts as his housekeeper. Why does he retain her? Merely because she is stone-deaf. Why does he want a deaf woman to wait upon him? Because there are sometimes noises in the house which would arouse the curiosity of any who chanced to overhear them." "We must discover the identity of the person concealed," remarked the girl with the big blue eyes, as she lay back lazily among the cushions. "We must. At all costs I intend to solve this mystery. Marigold," he said, removing his pipe from his lips and looking straight into her eyes, "my own belief is that you have discovered some very strange and startling drama of our complex London life—one which, when investigated, will prove to be astounding." "Do you really think so?" asked the girl, looking into his handsome face. "Yes—I do. Up to the present all our efforts have been in vain," he said. "Only one fact has been established, and that is that there is a prisoner—whether voluntary or not we cannot tell—in that creeper-covered house. We both saw Boyne creep up with food to him, while I saw his light beneath the door. Somebody is living up there in secret. Is it a man, or is it a woman? His eagerness makes me think that it is a woman. Who is it?" "Somebody he is shielding—somebody who has committed some serious crime, who fears to show his or her face lest it be recognised by agents of Scotland Yard." "Really, Marigold, you are very acute," he exclaimed. "We have had so many murder mysteries since the war, and in all of them the police confess their utter confusion, that the present situation fills me with great apprehension." "I know," she said. "But why not let us begin again? Let us watch the house. I’ll watch one night, and you watch the next. Surely we can by that means discover the truth. If the place is watched every night, this man Boyne must, in the end, be defeated." "But I thought you liked Boyne?" "Yes; he has been always very good to me. Remember that he is the owner of the place, and my aunt is his housekeeper," replied the girl. "I quite appreciate your point," said Durrant. "But if we are to fully delve into the affair we must not be influenced by the fellow’s open heart. The greatest criminals of the world have always been those who have been popular on account of their bonhomie and generosity."