"If you were to search all England," said he, "I don't suppose you could find a household more self-contained or free from outside influences. Whole weeks would pass and not one of them go past the garden gate. The Professor was buried in his work and existed for nothing else. Young Smith knew nobody in the neighbourhood, and lived very much as his employer did. The two women had nothing to take them from the house. Mortimer the gardener, who wheels the bath-chair, is an Army pensioner -- an old Crimean man of excellent character. He does not live in the house, but in a three-roomed cottage at the other end of the garden. Those are the only people that you would find within the grounds of Yoxley Old Place. At the same time, the gate of the garden is a hundred yards from the main London to Chatham road. It opens with a latch, and there is nothing to prevent anyone from walking in.
"Now I will give you the evidence of Susan Tarlton, who is the only person who can say anything positive about the matter. It was in the forenoon, between eleven and twelve. She was engaged at the moment in hanging some curtains in the upstairs front bedroom. Professor Coram was still in bed, for when the weather is bad he seldom rises before midday. The housekeeper was busied with some work in the back of the house. Willoughby Smith had been in his bedroom, which he uses as a sitting-room; but the maid heard him at that moment pass along the passage and descend to the study immediately below her. She did not see him, but she says that she could not be mistaken in his quick, firm tread. She did not hear the study door close, but a minute or so later there was a dreadful cry in the room below. It was a wild, hoarse scream, so strange and unnatural that it might have come either from a man or a woman. At the same instant there was a heavy thud, which shook the old house, and then all was silence. The maid stood petrified for a moment, and then, recovering her courage, she ran downstairs. The study door was shut, and she opened it. Inside young Mr. Willoughby Smith was stretched upon the floor. At first she could see no injury, but as she tried to raise him she saw that blood was pouring from the underside of his neck. It was pierced by a very small but very deep wound, which had divided the carotid artery. The instrument with which the injury had been inflicted lay upon the carpet beside him. It was one of those small sealing-wax knives to be found on old-fashioned writing-tables, with an ivory handle and a stiff blade. It was part of the fittings of the Professor's own desk.
"At first the maid thought that young Smith was already dead, but on pouring some water from the carafe over his forehead he opened his eyes for an instant. `The Professor,' he murmured -- `it was she.' The maid is prepared to swear that those were the exact words. He tried desperately to say something else, and he held his right hand up in the air. Then he fell back dead.
"In the meantime the housekeeper had also arrived upon the scene, but she was just too late to catch the young man's dying words. Leaving Susan with the body, she hurried to the Professor's room. He was sitting up in bed horribly agitated, for he had heard enough to convince him that something terrible had occurred. Mrs. Marker is prepared to swear that the Professor was still in his night-clothes, and, indeed, it was impossible for him to dress without the help of Mortimer, whose orders were to come at twelve o'clock. The Professor declares that he heard the distant cry, but that he knows nothing more. He can give no explanation of the young man's last words, `The Professor -- it was she,' but imagines that they were the outcome of delirium. He believes that Willoughby Smith had not an enemy in the world, and can give no reason for the crime. His first action was to send Mortimer the gardener for the local police. A little later the chief constable sent for me. Nothing was moved before I got there, and strict orders were given that no one should walk upon the paths leading to the house. It was a splendid chance of putting your theories into practice, Mr. Sherlock Holmes. There was really nothing wanting."