He had more than once during his career found himself obliged to enter other people's houses in this unceremonious, not to say burglarious fashion. But it was always an exciting experience; and his heart beat a trifle faster than usual as he stood motionless by the window, straining his ears for the sound of any movement on the part of the household. Nothing stirred, however, and by the help of an occasional gleam from his pocket electric torch Gimblet made his way to the door, and through the deserted house to the distant passage leading to the old tower. Once inside the library he breathed more freely, and when, after holding his breath for some minutes, he had made certain that the absolute silence of the place continued unbroken by any suspicion of noise, he felt safer still. His first act was to draw the curtains, and to fasten them together in the middle with a large safety-pin he had brought for the purpose. Then, secure from observation, he switched on his torch, placed it on the table with its back to the window, and set about what he had come to do. As he had not failed to observe, earlier in the day, the book-lined walls of the library were broken, opposite the window, by a panelled alcove where a small table stood, beyond which, against the wall, was a very large and tall grandfather's clock of black and gold lacquer, in imitation of the Chinese designs so popular in the eighteenth century. Among Lord Ashiel's last words, "The clock" had been uttered immediately after the detective's own name. No doubt they formed part of a message he wished to convey; and, though they might refer to any clock in or out of the house, it seemed to Gimblet worth while to begin his investigations with the one nearest at hand, and he turned his attention to it without loss of time. Gimblet was a connoisseur of the antique, and a few minutes' examination proved to him that this was a genuine old clock, untouched by the restorer's hand, and in an excellent state of preservation. The works appeared all right as far as he could make out, but through the narrow half-moon of glass, so often inserted in the cases of old clocks for the purpose of displaying the pendulum, that article was not to be seen, and he found that it was missing from inside the case, as were also the weights, so that it was impossible to set it going. There was one odd thing about it, which the detective had already remarked: it was firmly fixed to the wall by large screws, and he thought that there must be some opening through the back into a receptacle contrived in the panelling behind it. The case was so large that he was able to get inside it, and examine inch by inch the wood of the interior, which was lacquered a plain black.