Bell saw white smoke spewing from the brake shoes under every car, and the train clashed and banged to a halt halfway across the trestle. Instantly, the locomotive emitted five puffs of steam from its whistle. Five whistles signaled a brakeman to jump from the rear car—Preston Whiteway’s private carriage—and run back along the tracks waving a red flag to warn trains steaming behind it that the special had stopped suddenly for an emergency and was blocking the tracks. By then Bell had overflown the train and the trestle.

He saw the glitter of sunlight on glass.

In the same instant, he spotted the Thomas parked in the shadow of a rail-maintenance shack. The sun flashed again on a telescope sight. He counted two rifles braced on the roof of the shack, spitting red fire.

It was a brilliantly laid trap—the train stopped as a distraction, the rock-steady shooting position, the shock of total surprise. And Bell knew that if he were the young aviatrix whose name was painted on the side of his yellow monoplane, Frost would have killed her in the second hail of fire when she veered away instinctively, thus presenting a bigger target broadside.

Isaac Bell dove straight at the shack, sheered away at the last moment to aim clear of his propeller, and emptied his Remington’s five-shot magazine so fast that the sound of the shots blended together in a roar like a cannon. Circling up and back, he saw that he had hit the gunmen to either side of Frost. He extracted the empty magazine, slipped a full one in its place, and dove again.

Frost did not shoot at him. Bell wondered if he had hit Frost, too, and wounded him too badly to fight. But, no, Frost was running to the Thomas. He cranked the motor, jumped in, and drove onto the tracks. Then, to Bell’s puzzlement, he jumped from the auto and knelt briefly beside the rails.

Frost jumped back on the Thomas and drove toward the hills.

Less than ten seconds had expired since the shooting started. Detectives were still leaping from the hangar car. Bell banked hard to chase after the Thomas. But as the Eagle tipped on its side, Bell’s experience with Harry Frost’s relentless cruelty made him look carefully where Frost had knelt.

He saw smoke, a thin white trail of smoke.

Without hesitation, Isaac Bell rammed his blip switch, shoved his wheel forward, and dropped the Eagle toward the tracks. In the midst of the smoke, traveling along the rail, was a moving stud of red fire. Harry Frost had knelt on the rails and coolly lit a fuse—the fuse he had stolen from the Burbank maintenance shop along with detonators and dynamite.