“Maybe, but it is no affair of yours to interfere with private affairs of mine, Detective Sergeant. See here, there is no lady in these chambers. Secondly, I have an appointment at nine o’clock, and you are detaining me.” “What’s more,” answered Stokes, who had now quite lost his temper, “I intend to go on detaining you until I have searched these chambers and searched them thoroughly.” Nicol Brinn glanced at his watch. “If I leave in five minutes, I’ll be in good time,” he said. “Follow me.” Crossing to the centre section of a massive bookcase, he opened it, and it proved to be a door. So cunning was the design that the closest scrutiny must have failed to detect any difference between the dummy books with which it was decorated, and the authentic works which filled the shelves to right and to left of it. Within was a small and cosy study. In contrast with the museum-like room out of which it opened, it was furnished in a severely simple fashion, and one more experienced in the study of complex humanity than Detective Sergeant Stokes must have perceived that here the real Nicol Brinn spent his leisure hours. Above the mantel was a life-sized oil painting of Mrs. Nicolas Brinn; and whereas the great room overlooking Piccadilly was exotic to a degree, the atmosphere of the study was markedly American. Palpably there was no one there. Nor did the two bedrooms, the kitchen, and the lobby afford any more satisfactory evidence. Nicol Brinn led the way back from the lobby, through the small study, and into the famous room where the Egyptian priestess smiled eternally. He resumed his place upon the hearthrug. “Are you satisfied, Detective Sergeant?” “I am!” Stokes spoke angrily. “While you kept me talking, she slipped out through that study, and down into the street.” “Ah,” murmured Nicol Brinn. “In fact, the whole business looks very suspicious to me,” continued the detective. “Sorry,” drawled Brinn, again consulting his watch. “The five minutes are up. I must be off.” “Not until I have spoken to Scotland Yard, sir.” “You wish to speak to Scotland Yard?” “I do,” said Stokes, grimly. Nicol Brinn strode to the telephone, which stood upon a small table almost immediately in front of the bookcase. The masked door remained ajar. “You are quite fixed upon detaining me?” “Quite,” said Stokes, watching him closely. In one long stride Brinn was through the doorway, telephone in hand! Before Stokes had time to move, the door closed violently, in order, no doubt, to make it shut over the telephone cable which lay under it! Detective Sergeant Stokes fell back, gazed wildly at the false books for a moment, and then, turning, leaped to the outer door. It was locked! In the meanwhile, Nicol Brinn, having secured the door which communicated with the study, walked out into the lobby where Hoskins was seated. Hoskins stood up. “The lady went, Hoskins?” “She did, sir.”