“Oh,” said the Chief, “that ought to tell us something!” “It does,” answered the official. “We’ve submitted it to our small arms expert, and he pronounces it to be a bullet fired by an automatic pistol of unusually large calibre.” The Chief looked at Desmond. “You were right there,” he said. “And,” the official went on, “our man says, further, that, as far as he knows, there is only one type of automatic pistol that fires a bullet as big as this one!” “And that is?” asked the Chief. “An improved pattern of the German Mauser pistol,” was the other’s startling reply. The Chief tapped a cigarette meditatively on the back of his hand. “Okewood,” he said, “you are the very model of discretion. I have put your reticence to a pretty severe test this morning, and you have stood it very well. But I can see that you are bristling with questions like a porcupine with quills. Zero hour has arrived. You may fire away!” They were sitting in the smoking-room of the United Service Club. “The Senior,” as men call it, is the very parliament of Britain’s professional navy and army. Even in these days when war has flung wide the portals of the two services to all-comers, it retains a touch of rigidity. Famous generals and admirals look down from the lofty walls in silent testimony of wars that have been. Of the war that is, you will hear in every cluster of men round the little tables. Every day in the hour after luncheon battles are fought over again, personalities criticized, and decisions weighed with all the vigorous freedom of ward-room or the mess ante-room. And so to-day, as he sat in his padded leather chair, surveying the Chief’s quizzing face across the little table where their coffee was steaming, Desmond felt the oddness of the contrast between the direct, matter-of-fact personalities all around them, and the extraordinary web of intrigue which seemed to have spun itself round the little house at Seven Kings. Before he answered the Chief’s question, he studied him for a moment under cover of lighting a cigarette. How very little, to be sure, escaped that swift and silent mind! At luncheon the Chief had scrupulously avoided making, the slightest allusion to the thoughts with which Desmond’s mind was seething. Instead