"If they splash us," snapped Vinson, "we're lost; that damned machine can send a collection of its own kind to catch us before we can get to shore in a rubber boat." Yet Harry kept his course, his face set hard and his teeth clenched tight. His hand toyed with the throttle and the manifold pressure, testing and trying to eke another few revolutions per minute from the whirling propellers. His controlling hand was tight as a wrench upon the wheel, immobile and determined. The other plane edged closer; inches separated the wingtips, and the air, though smooth, caused the all too close wingtips to move and jockey above and below one another; to move closer and then to separate a bit. Then the second plane raced across Vinson's course and slowed down. It rose above him and began to drop down upon him. Vinson grunted and shoved the wheel forward. His flying boat went into a long, shallow dive. And with him went his too-close pursuit. Vinson swore. No chance of outdistancing them by going into a dive for extra speed. Then to forestall another such attempt, one of the planes near broadside of Vinson dove below him and began to climb. "Boxed," he groaned. * * * * * Inside of the nearby planes, Vinson could see the crews fighting the controls to no avail. Their faces were white from strain, and from fright, and their gestures indicated that they were fighting for him but were completely helpless. Only Vinson truly realized just how helpless they were. But Vinson was wrong. From one gun-port there came hurtling a square ammunition case. No machine, it; just a rectangular box of metal. It flew from the plane ahead and went in a brief arc out and across, to crash into the outboard motor on the port side of the plane just to Vinson's right. The plane bucked and lost flying speed, its engine racking itself from the wing with the out-of-balance propeller. From the opposite waist of the leading plane came another ammunition case which missed; then another which hit the leading edge of the wing. It cut deep and the cut edge of the wing ripped open. The wing began to vibrate wickedly and the plane slowed as the airfoil section spoiled. Vinson waved a hand just as the inboard engines on the plane ahead belched flame and came whining to a sullen stop. As Vinson drove ahead of the stricken plane ahead, the mechanic waved a burned arm and a section of the fuel line. His face was a mingled expression of pain and satisfaction. There were full minutes more. Planes drove in sidewise; all that were able to meet Vinson's plane came in darting for him but were sabotaged as they came. Vinson threw his controls rapidly, avoiding trouble, and then he was free and clear, out in the open, with the nearest plane behind. Not far behind; only twenty feet, but far enough to permit both Vinson and the girl to take a deep breath.