"One or more pear trees. "You will find these shrubs," handing him a list. "On that farm there are two horses, a bay and sorrel. "There is a black and white cow. "There are some leghorn chickens. "There is a collie dog." McCall, Jimmy and Brasher were startled. They stared at the old man in disbelief. McCall said: "Oh, I say, Professor, see here--" He stopped. He saw Matthews grin and wink at Jimmy. Professor Brierly was oblivious to the interruption. He continued: "The fish line contains all the characteristics of the rope, but was not at that place for so long a time." He looked once more at his slip of paper. "I forgot to mention that a stream of water runs through or adjacent to the place where these ropes were kept." He looked once more at his notes and shook his head. "The twine," he said slowly, "was also at that place for a considerable length of time. In addition, it appears to have been for some time in a hat factory, where felt hats are made; in a part of a hat factory where a good deal of the fur from the felt hats is in constant motion. I am not familiar with hat factories, but it must be in a branch of the factory, where the hat is worked after it has been dyed." He caught the detective's look of astonishment. "Really, Mr. Brasher, there is nothing remarkable about this. Your feat of finding the rope was far more meritorious, both the reasoning and the actual finding of the rope. What John and I did just now was absurdly simple. "All you need do now, Mr. Brasher, is find a man, probably a left-handed man, who lives on a place such as I described, who owns a motorcycle who cannot account for the time in which we know Mr. Miller was killed; who either worked in or had access to a hat factory; a man who has a pair of climbing irons and you have the murderer." "Oh, yeah, is that all?" Professor Brierly bristled. "What is there difficult about that? That should be simple. Surely there are not a great many farms or farmyards that comply with all the conditions I enumerated. Surely that should be merely detail, just the work the police ought to be able to do. Ex-Police Commissioner McGuire thinks that too." He waved his hands with a gesture of finality and Brasher knew that he was dismissed. With a look of awe and reverence he departed, shaking his head wonderingly. Professor Brierly was also shaking his head. There was a puzzled frown on his fine features. He said: "I shall have to recast my opinion about the man or men who are responsible for these two murders. I said he or they are clever but not subtle. I was wrong, there is a subtlety about it, a devilish ingenuity about it." He shook his head once more, the puzzled frown becoming deeper. "There are things about these two murders that do not fit and it seems hard to make them fit. I wonder--" He shook his head violently as if to clear it of an unpleasant or hazy thought. Hale began, slowly, not knowing how to broach the subject: