“It isn’t a question of thinking,” he replied. “It was certainly not suicide. There are the plainest indications of homicide; and, of course, in the particular circumstances, homicide means murder.” I was thunderstruck. In my own mind I had dismissed the case somewhat contemptuously as a mere commonplace suicide. As my friend had truly said, I had accepted the obvious appearances and let them mislead me, whereas Thorndyke had followed his golden rule of accepting nothing and observing everything. But what was it that he had observed? I knew that it was useless to ask, but still I ventured on a tentative question. “When did you come to the conclusion that it was a case of homicide?” “As soon as I had had a good look at the place where the body was found,” he replied promptly. This did not help me much, for I had given very little attention to anything but the search for the keys. The absence of those keys was, of course, a suspicious fact, if it was a fact. But we had not proved their absence; we had only failed to find them. “What do you propose to do next?” I asked. “Evidently,” he answered, “there are two things to be done. One is to test the murder theory--to look for more evidence for or against it; the other is to identify the murderer, if possible. But really the two problems are one, since they involve the questions, Who had a motive for killing Cyrus Pedley? and Who had the opportunity and the means?” Our discussion brought us to the station, where, outside the hotel, we found Mr. Pedley waiting for us. “I am glad you have come,” said he. “I was beginning to fear that we should lose this train. I suppose there is no new light on this mysterious affair?” “No,” Thorndyke replied. “Rather there is a new problem. No keys were found in your brother’s pockets, and we have failed to find them in the ditch; though, of course, they may be there.” “They must be,” said Pedley. “They must have fallen out of his pocket and got buried in the mud, unless he lost them previously, which is most unlikely. It is a pity, though. We shall have to break open his cabinets and drawers, which he would have hated. He was very fastidious about his furniture.” “You will have to break into his flat, too,” said I. “No,” he replied, “I shan’t have to do that. I have a duplicate of his latch-key. He had a spare bedroom which he let me use if I wanted to stay in town.” As he spoke, he produced his key-bunch and exhibited a small Chubb latch-key. “I wish we had the others, though,” he added. Here the up-train was heard approaching and we hurried on to the platform, selecting an empty first-class compartment as it drew up. As soon as the train had started, Thorndyke began his inquiries, to which I listened attentively. “You said that your brother had been anxious and depressed lately. Was there anything more than this? Any nervousness or foreboding?”