As the aviator turned his machine to reconnoitre in the new direction, he was surprised to see the hostile aeroplane between him and his objective. Absorbed in his scrutiny of the ground, he had all but forgotten it. It was slightly higher than himself and about half a mile distant. He could not carry out his reconnaissance without coming into fatal proximity to its machine-gun, and he could not return directly over the battle lines without passing between the crossed fires of this and the other machine now drawing close. Even as the realisation of his position flashed on him, a narrow slit appeared in one of his planes. The nearer of his foes was already firing. Quicker than thought he turned and raced off into the country behind the battle. A plan, the only one with a possible chance of success, had sprung into his mind. He had no intention of failing in this all-important mission of his. But first he must get out of the range of that deadly machine-gun. He dared not rise across it at barely half a mile range. At full speed he raced away, inclining his machine downwards. The hostile aeroplane followed, depressing her course likewise, to get him into the zone of her fire or to force him to the ground. The scout's speedometer registered 100 miles an hour. Beneath his feet he had glimpses of trees and houses and fields flitting past in a stream where salient features prolonged themselves into long blurred lines. They looked oddly large after the altitude at which he had been contemplating them. He threw a glance over his shoulder at his pursuers. The nearer was now rather more than a mile away. The other had apparently given up the chase. The clock showed 12.15; in less than two minutes he distanced his adversary by nearly a mile--he had therefore a superiority in speed of about twenty-five miles per hour. He did not consciously deduce this result. His trained mind working with incomputable swiftness under the stimulant of imminent danger gave the result like an intuition. His plan presented itself to him completely formed. At this distance he could risk the danger zone of the machine-gun for the few moments he would be in it. He swerved his machine upward and climbed steeply. In a minute the other aeroplane was level with him; beneath him. The scout rose along a slant, slowing down his engine until his pace was almost equal to that of the machine below. Both rose steadily. The battle din ceased altogether behind him. He flew in the seeming silence of the roar of his own engine and the deeper bass of the other machine, just audible, below. He bent forward over his map and picked out his approximate position. Then he noted a village some twenty miles in rear of the battle, and drew an imaginary line from it south-westward to the enemy's left flank. That village was to serve as turning-point. He should reach it, he calculated, at 12.27. The barograph indicated 3000 feet and still rising.