Truly the cobwebs are blown away from the brains and lungs of those who fly. Indeed, it is a chilly proceeding, even when indulged in during the dog days. Motoring without a wind-screen is considered rough by many people, but let them fly an aeroplane at forty miles an hour at 8,000 or 10,000 feet on any day. It is always chilly in the air, and by our thermometer that afternoon we both knew that we should have a cold night-flight. Beyond the little front garden of the farm, a square ill-kept grass patch, bordered by neglected standard roses, was a big grass-field, while beyond lay the open down sloping away to the valley. At each corner of the field we had already placed big acetylene lights, ready charged, so that after we left, old Theed could light them to show us our landing-place, for a descent at night is always dangerous, especially if there is no landmark and the night be dark. Through those exciting days of our sojourn at Holly Farm, I, assisted by Teddy and Roseye, had worked night and day attending to every detail. Indeed, at six o'clock that very morning--almost before the grey dawn--I had gone round to these four lamps, the intense white light of which would be visible for many miles, and lit and tested them in order to assure myself that all was in working order. The afternoon wore on. Mulliner brought us out cups of tea into the yard, for we were far too anxious and busy to think of the afternoon gossip. The days were lengthening, of course, but we found them all too short. This final experiment that we were undertaking would prove whether, after all, we had any effective defence against the terror of the night--or not. Try how I would, I could not put entirely away from myself the growing suspicion that, if spies had been so watchful, they would now be increasingly eager and ingenious in their endeavour to combat us. Once I laughed at those who told us there were German spies about us--I denounced them as scaremongers. But hard facts, shown to us in black and white, shown to us in prosecutions and actual executions of spies, had convinced me--as they must have convinced every Briton unless he were a pro-German or a lunatic--that dastardly secret agents existed even in the most unsuspected quarters, and that the Invisible Hand had been responsible for many a disaster to the British arms on land and at sea. Would that Hand still bring disaster upon myself? Daylight faded--and quickly. The evening was calm and clear, with an orange glow of sunset in the west. All was in readiness. My machine, with its big dual engines, its searchlight, its dynamo, and that most deadly apparatus contained in the brown deal box, stood in the yard running like clockwork, all its controls in order, every strainer taut, every nut locked, and the wooden petrol-container filled. All that was required was to wheel it out into the big grass-field and give the propeller a start.