He advanced the throttle to three-quarter speed. The plane was headed toward the Squadron. She was flying less than three hundred feet above the earth, and there could be no maneuvering now. The Nieuport would have to be flown level, carefully. The slightest piece of overcontrolling might rip the damaged tail assembly from the fuselage. Tex Langdon stared ahead, down. He groaned. He had forgotten the ground fog. It was spread over the earth, in the direction of the Squadron, like a grey-white blanket. Even below the ship now, the first wisps of it were drifting. And far ahead was the wing-drooping Nieuport, vanishing from sight into the grey stuff. Tex stiffened in the cockpit. Lieutenant Adams, once more winging away from his plane in the fog! He couldn’t be sure of it but he could guess. He had saved Adams from going down with Boche lead in his plane and body and the lieutenant again was winging in to leave him alone. Even with a drooping wing, he might have waited. Lieutenant Harrington _would_ have waited. It was Adams, all right. He reached for the throttle, but then he muttered to himself suddenly. The Nieuport that had vanished into the fog was in sight again! She was banking around, coming back! Tex held the little combat ship in level flight. He watched the other plane come on, his eyes wide. Her left wing drooped badly; she had banked around to the right. He caught sight of a helmeted head, an arm held out in the prop wash. The two ships rushed past each other. Tex stared back. Once again the Nieuport was banking to the right. She came around sluggishly, gained slowly on the throttled down sister plane. * * * * * Side by side, with less than twenty feet of grey air between the wing-tips, they flew now. And Tex recognized Lieutenant Adams. That officer was pointing toward his left wing-tip, which was in tatters toward the trailing edge, with one strut twisting back in the wind. The officer got a hand out in the prop wash, tilted it downward in a mild degree. Tex nodded. He pointed back toward his ship’s tail assembly, saw Lieutenant Adams twist his head, stare back. And then the veteran lieutenant nodded his head and banked slightly to the southward. Tex banked, too, very gently. The other Nieuport was nosing downward now and Tex moved the stick forward a bit. The movements of his plane were very sluggish, uncertain. Fog swept over both planes. Tex flew with his head half turned, watching the wing-tips of the other ship. Several times they were lost from sight, but each time he picked them up again. Both ships were flying throttled down. Seconds passed and they seemed hours. The fog was growing thicker.