By this time Blackie's lights were out of sight and Tam was alone. He looked down at his compass and the quivering needle now pointed to his right, which meant he was on the homeward track. He kept what he thought was a straight course, but the needle swung round so that it pointed toward him. He banked over again to the right and swore as he saw the needle spin round as though some invisible finger was twirling it. Now the airplane compass is subject to fits of madness. There are dozens of explanations as to why such things occur, but the recollection of a few of these did not materially assist the scout. The thing to do was to get clear of the clouds and take his direction by the stars. He climbed and climbed, until his aeronometer pointed to twenty thousand feet. By this time it was necessary to employ the apparatus which he possessed for sustaining himself at this altitude. It was amazing that the clouds should be so high, and he began to think that his aeronometer was out of order when he suddenly dived up into the light of a cold moon. He looked around, seeking the pole-star, and found it on his left. So all the time he had been running eastward. And then his engine began to miss. Tam was a philosopher and a philosopher never expects miracles. He understood his engine as a good jockey understands his horse. He pushed the nose of his machine earthward and planed down through an interminable bank of clouds until he found a gray countryside running up to meet him. There were no houses, no lights, nothing but a wide expanse of country dotted with sparse copses. There was sufficient light to enable him to select a landing-place, and he came down in the middle of a big pasture on the edge of a forest of gaunt trees. He unstrapped himself and climbed down, stretching his limbs before he took a gentle trot around the machine to restore his circulation. Then he climbed back into the fuselage and tinkered at the engine. He knew what was wrong and remedied the mischief in a quarter of an hour. Then he inspected his petrol supply and whistled. He had made a rough calculation and he knew within a few miles how far he was in the interior of Germany, and by the character of the country he knew he was in the marshy lands of Oosenburg, and there was scarcely enough petrol to reach the Rhine. He left his machine, slipped an automatic pistol into the pocket of his overall and went on a voyage of exploration. Half a mile from where he landed, he struck what he gathered was a high-road and proceeded cautiously, for the high-road would probably be patrolled, the more so if the noise of his machine had been correctly interpreted, though it was in his favor that he had shut off his engines and had planed down for five miles without a sound.