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.

He had packed the trestle with explosives, Bell realized. The attack he had planned had been twofold: shoot Josephine out of the sky, and blow Preston Whiteway’s train to Kingdom Come – along with every Van Dorn riding on it.

Bell forced the Eagle down and straddled the rails with the skids. He hit so hard, the machine bounced and tried to rise again. It would have been safer to pour on the power and take her up again, but there wasn’t a moment to lose. He drove the machine down hard and felt the skids shatter on the crossties. Splintering wood, shrieking metallic protest, the Eagle slid along the railroad tracks. Bell leaped and hit the ground running.

The smoke was racing ahead of him, picking up speed as it closed with the trestle. Bell ran faster, gaining on it, and was within yards of stomping it out when it slipped over the lip of the gorge and under the trestle where he couldn’t reach.

“Back your engine!” he shouted, running onto the trestle. “Back off the bridge.”

There was no time for that. He saw the engineer gaping from his cab and his detectives running to help him, not realizing the danger. He saw Dashwood among them.

“Dash!” he shouted. “There’s a detonator fuse under the tracks. Shoot it.”

Bell climbed over the edge and down through the wooden timbers beneath the track. He saw the fuse strung timber to timber, burning brightly. Dash was quick – he, too, went over the side, scrambled among the timbers, and spotted the dot of fire fifty feet away. Clinging to a timber with one arm, the young detective drew his long-barreled Colt, took aim, and fired. The bullet threw splinters. The fuse kept burning. Dash fired again. The fuse leaped and jumped, and kept burning.

Bell pulled himself along under the tracks, jumping from timber to timber. Ahead, in the shadow of the locomotive, he saw bundled dynamite – dozens and dozens of sticks, enough to destroy the trestle, the train, and everyone on it. Dash fired again. The fuse fire danced on.

Isaac Bell leaped onto a horizontal cross timber, drew his Browning smoothly from his coat, and fired once.

The dancing flame vanished. A wisp of smoke stood in its place, wavered in a puff of wind, then drifted away as if the fuse had been a candle snuffed out to end a pleasant evening.

Bell scrambled back up on the tracks and ran to the train to issue orders.

Josephine’s Van Dorn mechanicians were good men but city men, next to useless out of doors. “Crank Whiteway’s roadster,” he told them, “and run it down the ramp. Defuse the dynamite under the bridge. Then fix the skids so my machine can fly.

“Dash! You cover the boys working on my machine. Shoot Frost in the head if the sidewinder doubles back.” He gestured Dash closer, and added under his breath, “Don’t let Celere near my machine. Oh, by the way, I know your mother gave you that Colt. But I would take it kindly if you would allow my gunsmith to fix you up with a proper Browning.

“Texas Walt! You come with me!”

Bell jumped behind the steering wheel of Preston Whiteway’s yellow Rolls-Royce. Walt Hatfield piled in next to him with a couple of lever-action Winchesters, and they drove off the trestle and raced up the railroad tracks toward the foothills of the Coast Range.

After three miles of the grade steepening and scrub growth and clumps of low trees intruding on the grassland, they found the Thomas Flyer stopped in the middle of the tracks with two tires punctured by loose railroad spikes. Texas Walt spotted Frost’s trail, first from loose ballast where he had run down the railroad embankment, then from his trampling through the knee-high grass.

Bell covered the thickets and rock outcroppings ahead with a Winchester while Hatfield loped from a scuff in the sand to a bent blade of grass to a broken twig. Bell himself was an experienced tracker, but Texas Walt could read the ground like the Comanches who had raised him.

Above the hills, thunder muttered and lightning flickered inside the swelling storm clouds. The wind puffed cold in their faces, then hot.

A blue jay bounced up from a thicket of evergreen oaks a half mile ahead.

It was mighty long range for a rifle, but Bell snapped, “Down!”

A shot echoed off the hills. Walt crumpled beside him.

BELL CUT TO THE RIGHT, seeking the shelter of a boulder. A.45-70 slug parted the air six inches from his cheek. Instead of diving for cover, he bounded past the boulder and into a narrow arroyo.

He raced silently up the dry creek bed, one eye ahead, the other guiding his boots around anything that would make noise. The arroyo veered more to the right – farther from Frost – even as it climbed the steepening slope. Bell put on speed. He ran flat out for a full mile, climbing all the distance. When he finally stopped to catch his breath, it was where a ledge would allow him to survey the ground he had put behind him. Slithering flat on his belly, he edged forward until he could see the back of the thicket from which Frost had fired.

Now half a mile below him, it covered nearly an acre of the hillside. Frost could be hidden anywhere inside it or he might have retreated up the slope and could now be more at Bell’s level. If he were smart, he would have withdrawn. But Bell was betting that Frost was making a big-game hunter’s mistake by staying still or moving only a short distance to lay another ambush for his quarry. Most animals ran when hunted. Some, like panther and elephant, might occasionally charge. Very few slipped past to attack from behind.

Bell chose the route for his attack down a shallow arroyo and past a thicket. He eased back from the ledge to stay out of sight and started down. He was silent and he was quick, loath to give Frost time to reconsider his position. When the arroyo grew too shallow to hide him, he crawled to the nearest thicket and kept going.

The leaden arch of sky was pierced suddenly by jagged lightning.

Drops of rain scattered the dust.