If Steve Stevens managed to finish, all the better—Celere would sell the Army heavy bombers as well as nimble escorts. But that was a very big if. Uncontrollable vibration, due to a failure to synchronize the twin engines, was shaking it to pieces. If Stevens smashed before he finished, Celere could blame it on the farmer’s weight and poor flying. He had to admit that, by now, young Igor Sikorsky would have solved the vibration problem, but it was beyond Celere’s talents. And it was too late in the game to steal those ideas even if Sikorsky were here instead of in Russia. If only the thermo engine he had bought in Paris had worked out, but that, too, had been beyond his talents.

THE VAN DORN PROTECTIVE SERVICES operators guarding the roof of the armory had kept a sharp eye on the door from the stairs, as instructed by Joseph Van Dorn, though every cheer that went up had drawn their attention to the parade ground and bleachers below and the next machine descending from the sky.

Now they lay unconscious at Harry Frost’s feet, surprised by hammer blows of his fists after he sprang not from the stairs’ penthouse but from the elevator’s, where he had hidden since dawn.

Frost steadied a Marlin rifle on a square stone between two notches in the parapet and waited patiently for Josephine’s head to completely fill the circle of his telescopic sight. She was coming straight at him, preparing to circle the armory as required by the rules, and he could see her through the blur of her propeller. This might not be as satisfying a kill as strangling her, but the Van Dorns had left him no opportunity to get close. And there were times a man did best to take what he could get. Besides, the telescope made it seem as if they were facing each other across the dinner table.

THE INSTANT ISAAC BELL saw the stone notches in the armory’s crenellated parapet, he rammed his control wheel forward as hard as he could and made the Eagle dive. That roof was precisely where he would lay an ambush. The rules of the race guaranteed that Frost’s victim would have to fly so close, he could hit her with a rock.

Driving with his right hand, he swiveled his Remington autoload rifle with his left. He saw a startled expression on Josephine’s face as he hurtled past her. Ahead, among the stone notches, he saw the sun glint on steel. Behind the flash, half hidden in shadow, the bulky silhouette of Harry Frost was drawing a bead on Josephine’s yellow machine.

Then Frost saw the American Eagle plummeting toward him.