"You have?" said Brett, with the slightest tinge of sarcasm in his voice. "Did you do this?" and he commenced to thump with a clenched fist upon every portion of the external screen that he could reach. "No, we did not," said the policeman, "and I don't see that it is going to accomplish anything except hurt your hand." "That may be so," murmured Brett; "but the diamonds went this way and none other." He tested every portion of one window screen in this manner without effect. Then he approached the second window, and, beginning at the left-hand top corner, did the same thing. Suddenly an exclamation came from the three interested watchers. In the centre of the lower part of the screen Brett's hand made a visible impression upon the iron wire. Using no more force than had been applied to other portions, the blow served to tear a section of the blind about eight inches across. Instantly the barrister ceased operations, and, producing a pocket-microscope, minutely examined the rent. "I expected as much," he said, taking hold of the torn part of the screen and giving it a vigorous pull, with the result that a small piece, measuring about eight inches by six, came bodily out. "This has been cut away, as you will see, by some instrument which did not even bend the wire. It was subsequently replaced, whilst the fractured parts were sufficiently cemented by some composition to retain this section in its place, and practically defy observation. There was nothing for it but force to reveal it thus early. No doubt in time the composition would have dried, or been washed away, and then this bit of the screen would have fallen out by the action of wind and weather. Here, at any rate, is a hole in your defensive armour." He held out the _pièce de conviction_ to the discomfited Sharpe, who surveyed it in silence. It was no part of Brett's business in life, however, to snatch plaudits from astounded policemen. "This is a mere nothing," he continued. "Of course, there must have been some such means of getting the diamonds off the premises. Let us return to the ante-room and there you can tell me the exact history of events on Monday evening." CHAPTER IV THE MURDERS In less confident tones Inspector Walters resumed his narrative--