Intent on getting their mail pouch to the airport in record time, the eyes of Don, Garry and Chick, in the Dragonfly, were peering forward and downward to locate the wind-cone, get wind direction and save every precious second even during the approach to the runway.

Unexpected, startling, disconcerting, there came, not a hundred feet in front of the nose, the roaring hiss of a rocket rising to burst, in a brilliant, eye-stunning flash of vivid white just ahead.

Don instinctively side-slipped.

The flash, coming without warning, upset his self-control, made him think that he might be plunging his chums into some unseen danger. To speed into that area of still blazing fire was unthinkable.

Don’s side-slip got the ship away fifty feet: then he caught the wings, brought the ship to its forward, level flight.

Roaring upward, a second messenger of terror, with its blazing tail, seemed to be coming straight under the right wing. Garry, seeing it, screamed a warning into the helmet communication tube.

“Don—one’s coming—bank left!”

Don kicked rudder, moving the stick to tip the wings. He gunned up, in the bank.

The ship swung, almost on wingtip.

Again almost ahead of the new swing, came that terror from below.

Don saw it. He skidded out of the turn by giving excess rudder, caught the skid, and swiftly adjusted stick and bar to get on a level keel.

His quick wit told him that they were almost exactly at the altitude where those deadly fireworks were bursting.

In their excited, upset state all three youths supposed the rockets were the result of some sort of celebration. The real meaning did not occur to them.

One thing they all realized was that they were over an area of the utmost danger: no mind could foresee the track of bomb or rocket.

“They don’t see us, don’t know we’re up here!” Chick muttered as Don planned his next moves with quick and cool precision. Don had regained his self-control.

“I’ll dive, to get away with the greatest speed!” Don had decided.

Nose down, engine full speed, he dived.

The needle of the altimeter began to hasten its backward swing.

A brilliant shaft of white struck upward, picking them out, throwing up around them a sea of vivid illumination.

Instantly Don changed his tactics.

To level off, as he intended, to come out of the dive with still a fair margin of altitude to give him ease of handling well above earth was impossible. The searchlight might prevent him from seeing the ground, might blind him.

He was plunging straight down toward it.

Full-gun, he drew back on the stick. Up tipped the nose.

Wires sang with the fierce wind. The ship trembled.

At nearly two hundred miles an hour the ship began to climb in the huge arc of a “loop.”

Don had purpose behind his shift of plan.

While he had never executed it in darkness, he recalled the maneuver known as an Immelmann Turn, said to have been devised by a German war ace, by which altitude above an adversary was gained swiftly, with a change of flying direction.

As the ship soared on its vast curve, it came, soon, to the top of the loop. It was precisely “on its back,” upside down. The controls were heavy, inert in response.

Had he maintained control elements in the same position the engine should have carried the ship, with its speed almost nil, just to the point where the nose would have dropped by engine weight, acted on by gravity.

Then, going down on the descending side of the wide arc, it could be caught, at the bottom of the loop, leveled, and sent onward.

Don did not delay for that to happen.

Instead he shifted the stick far to the side, holding it there.

Before the nose dropped, the slight forward speed enabled the ailerons to act: the wing dropped, the other came up, and since Don held the slick steady, the ship, from being on its back, executed half of a “barrel roll,” so that it was right side up, and, naturally, at the top of a big circle, pointing its nose exactly backward from its original direction.

Quickly Don caught the ship’s wings as it turned on its fore-an-aft axis.

Thus he had climbed to the top of a big loop, had turned the ship from being upside down to the correct flying position, facing back on the course.

He kept the throttle full open, flying level for an instant.

They were looking away from the search-lamp. Its beams no longer menaced Don’s clear vision. Besides, being so much higher, the rays were spread, diffused.

But they were going back, and for all that Don knew, the force of rockets might still enable the missiles to reach them.

He knew, with sureness, that no chance celebration accounted for the rockets, by that beam of light coming up at them from a spot where no searchlight should have been!

He wanted to be doubly safe, to return to the proper course.

He began, almost immediately, a banked turn, at the same time going upward. In that climbing turn they both gained altitude and returned gradually to the proper course. Chick clamped his gauntleted hands.

“Good work!” he screamed in shrill elation.

Garry, too, commended, his voice more subdued as he realized that his tones went through a tube directly into ear outlets clamped close to the young pilot’s head.

“Fine, Don!” he complimented the flyer.

Don nodded his appreciation.

His face, though, was still creased with lines of concern.

“That’s somebody with a deadly purpose!” he murmured. “No fireworks were being sent up for fun. They were meant to upset us. Who could be so mean? Where did that searchlight beam come from? The airport? I was too excited to be able to trace it—right in my eyes, the way it was.”

He peered over the side: the rays were gone.

The nose was coming toward its proper point. Don adjusted his controls. They had first made a great circle, outward from its center, and upward in its arc. Then they had continued to climb, but in an arc that was on a different plane.

It took them far out over the swamp.

Garry, sighting the airport, saw that Don brought the nose to its proper line with the revolving beacon as the beam flicked past in its blinking circuit of the skies.

Chick, staring, with neck craned, over the side, saw something far more deadly.

“Garry!” he yelled at the top of his capacity, “tell Don—helicopter coming—up——”

Garry caught the call, but not its import.

He followed the line of Chick’s pointing arm.

Precious seconds were thus expended.

The strange, menacing craft gained an advantage in the delay of locating it and of discovering its purpose.

Don had to be told. Then he was in such a position that the left wing hid the object of Garry’s excited explanation.

Garry, over the edge of the wing, saw that the helicopter, its horizontal blades bringing it higher, the tractor propeller drawing it forward, rose toward them on a slanting line that seemed meant to bring the odd craft up under their own ship.

Chick, as Don altered the course to get the wing out of his line of vision, sent over a parachute flare, lighting up the scene with its white, revealing gleam.

Don saw their adversary.

From that had come the rockets: he felt sure of it. Flung out, or discharged from some outboard contrivance, their ignition powder had sent them in calculated proximity to the Dragonfly—for some deadly purpose!—to put the ship out of control, no doubt!

“There’s a man in that cockpit!” Garry told Don, better able to see past the swiftly revolving horizontal blades as Chick’s flare turned night into day beneath them.

Chick, looking, saw more.

“It’s—it’s—” he could hardly make his lips form the words. “It’s the—Thing that never—was—the Man who Never—Lived!”

He saw the green of the head covering, the slick, glistening, formless body in its slippery oilskins, the flicker of light reflected from shiny rubber gloves.

Up at them came the helicopter, its course calculated to fall on an angle that would drive them upward, or turn them away from the airport, or—if Don sought to side-slip—bring them on a level with that dreadful Thing at its controls.

What then? In any maneuver they could execute, Don wondered, what would that Thing do?