We slowed down with extraordinary rapidity, and still peering ahead we went dead-slow through it. I had not put on my goggles after leaving King’s Lynn, and the dust stung and smarted in my eyes. It was not, therefore, a belt of fog, but real road-dust. And at the moment we crept through it I felt Harry’s hands on my shoulder. “There’s something just ahead,” he said. “Look! don’t you see the tail light?” As a matter of fact, I did not; and, still going very slow, we came out of that dust-cloud. The broad empty road stretched in front of us; a hedge was on each side, and there was no turning either to right or left. Only, on the right, was a lodge, and gates which were closed. The lodge had no lights in any window. Then we came to a standstill; the air was dead-calm, not a leaf in the hedgerow trees was moving, not a grain of dust was lifted from the road. But, behind, the dust-cloud still hung in the air, and stopped dead-short at the closed lodge-gates. We had moved very slowly for the last hundred yards: it was difficult to suppose that it was of our making. Then Jack spoke, with a curious crack in his voice. “It must have been a motor, sir,” he said. “But where is it?” I had no reply to this, and from behind another voice, Harry’s voice, spoke. For the moment I did not recognise it, for it was strained and faltering. “Did you open the syren?” he asked. “It didn’t sound like our syren. It sounded like, like----” “I didn’t open the syren,” said I. Then we went on again. Soon we came to scattered lights in houses by the wayside. “What’s this place?” I asked Jack. “Bircham, sir,” said he. GAVON’S EVE It is only the largest kind of ordnance map that records the existence of the village of Gavon, in the shire of Sutherland, and it is perhaps surprising that any map on whatever scale should mark so small and huddled a group of huts, set on a bare, bleak headland between moor and sea, and, so one would have thought, of no import at all to any who did not happen to live there. But the river Gavon, on the right bank of which stand this half-dozen of chimneyless and wind-swept habitations, is a geographical fact of far greater interest to outsiders, for the salmon there are heavy fish, the mouth of the river is clear of nets, and all the way up to Gavon Loch, some six miles inland, the coffee-coloured water lies in pool after deep pool, which verge, if the river is in order and the angler moderately sanguine, on a fishing probability amounting almost to a certainty. In any case during the first fortnight of September last I had no blank day on those delectable waters, and up till the 15th of that month there was no day on which some one at the lodge in which I was stopping did not land a fish out of the famous Picts’ pool. But after the 15th that pool was not fished again. The reason why is here set forward.