He would, he told himself, accept for the time being as _facts_ what, he admitted to himself, so far only seemed to be such. Hartley Parrish, then, had been seated in his library at his desk with the door locked. The fire was smoking, and therefore he had opened the window. According to Horace Trevert, the window had not been bolted when he had entered the library, for, after smashing the pane in the assumption that the bolt was shot, he had had no difficulty in pushing up the window. Hartley Parrish had opened the window himself, for on the nail of the middle finger of his left hand Robin had seen, with the aid of the magnifying-glass, a tiny fragment of white paint. Who had closed it? He had no answer ready to _that_ question. Now, as to the circumstances of the shooting. The suicide theory invited one to believe that Hartley Parrish had got up from his desk, pushing back his chair, had gone round it until he stood between the desk and the window, and had there shot himself through the heart. Why should he have done this? Robin had no answer ready to this question either. He passed on again. Bude had heard loud voices a very few minutes before Mary had heard the shot. That morning’s experiments had shown that Bude could have heard these sounds only by way of the open window of the library and the open doors of the garden and the library corridor. Additional proof, if Bude had heard aright, that the library window was open. Leaning back in his seat, his finger-tips pressed together, Robin Greve resolutely faced the situation to which his deductions were leading him. “The voice heard at the open window,” he told himself, “was the voice of the man who murdered Parrish and who closed the window, that is, of course, if the murder theory proves more conclusive than that of suicide.” This brought him back to his investigations in the rosery. The abrasure he had discovered on the timber upright was the mark of a bullet and a mark freshly made at that. Moreover, it had almost certainly been fired from the library window—from the window which Parrish had opened; the angle at which it had struck and marked the tree showed that almost conclusively. Yet there had been but one shot! If only he had been able to find that bullet in the rosery! Robin thought ruefully of his long hunt among the sopping rose-bushes. Yes, there had been only one shot. Mary Trevert had stated it definitely. Besides, the bullet that had killed Hartley Parrish had been fired from his own revolver and had been found in the body. Robin Greve felt the murder theory collapsing about him. But the suicide theory did not stand up, either. What possible, probable motive had Hartley Parrish for taking his own life? “He wasn’t the man to do it!” The wheels of the train took up the rhythm of the phrase and dinned it into his ears. “He wasn’t the man to do it!” The riddle seemed more baffling than ever.