"Smart chap, Cotman!" whispered Tansley to Brent. "That bit of cross-exam'll tell with the jury. And now, what next?" Bunning, recalled from the previous sitting, came next--merely to repeat that the Mayor went up to his parlour at twenty-five minutes past seven, and that he and Mr. Brent found his Worship dead just after eight o'clock. Following him came Dr. Barber, who testified that when he first saw Wallingford's dead body, just about a quarter-past eight, he came to the conclusion that death had taken place about forty-five minutes previously, perhaps a little less. And from him Cotman drew evidence that Wellesley, in the examination at the mortuary, was normal, calm, collected, and, added Dr. Barber, of his own will, greatly annoyed and horrified at the murder. Brent was beginning to get sick of this new development: to him it seemed idle and purposeless. He whispered as much to Tansley. But Tansley shook his head. "Can't say that," he replied. "Where was Wellesley during that nineteen minutes' absence from the surgery? He'll have to explain that anyway. But they'll have more evidence than what we've heard. Hello! here's Walkershaw, the Borough Surveyor! What are they going to get out of him, I wonder?" Brent watched an official-looking person make his way to the witness-box. He was armed with a quantity of rolls of drawing-paper, and a clerk accompanied him whose duty, it presently appeared, was to act as a living easel and hold up these things, diagrams and outlines, while his principal explained them. Presently the eager audience found itself listening to what was neither more nor less than a lecture on the architecture of Hathelsborough Moot Hall and its immediately adjacent buildings--and then Brent began to see the drift of the Borough Surveyor's evidence. The whole block of masonry between Copper Alley and Piper's Passage, testified Walkershaw, illustrating his observations by pointing to the large diagram held on high by his clerk, was extremely ancient. In it there were three separate buildings--separate, that was, in their use, but all joining on to each other. First, next to Copper Alley, which ran out of Meadow Gate, came the big house long used as a bank. Then came the Moot Hall itself. Next, between the Moot Hall and Piper's Passage, which was a narrow entry between River Gate and St. Lawrence Lane, stood Dr. Wellesley's house. Until comparatively recent times Dr. Wellesley's house had been the official residence of the Mayor of Hathelsborough. And between it and the Moot Hall there was a definite means of communication: in short, a private door. There was a general pricking of ears upon this announcement, and Tansley indulged in a low whistle: he saw the significance of Walkershaw's statement. "Another link in the chain, Brent!" he muttered. "'Pon my word, they're putting it together rather cleverly: nineteen minutes' absence? door between his house and the Moot Hall? Come!"