Holding the Dragonfly barely higher than the wires he must top as he took off, Don sent the craft toward the swamp.

As soon as they swept beyond the cottages that backed their small yards on the undrained swamp, Chick sent overside his first white-light parachute flare.

“It’s only for safety’s sake,” he muttered. “That young Indian, if he knows the swamp at all, has had time to get across to the Dart. But he might try to fool us, and stop to hide. Not likely—but we must be sure!”

He, and Garry, watched over the side, a little afraid that with the craft of his forefathers the red-skinned John might so cleverly crouch in the eel grass that they might not see him.

Don dropped the nose, however, allowing the Dragonfly barely to skim the low patches of water, and clumps of gently waving marsh vegetation.

As soon as they got beyond the vivid glow of the light slowly floating down toward the marsh, Don climbed the ship three hundred feet, came around, side-slipping to lose altitude as soon after the next flare was ignited and launched as he could.

By these tactics, continued for several minutes, the three chums satisfied themselves that the Indian was at least not visible; and if he remained hidden for that long they had him!

“By now,” Garry decided, as he strained his eyes overside, “the police must have gotten out here to surround the swamp. Mr. McLeod agreed to get the Chief to bring all his force, and to send out his private detectives, and get every waterman to help as guides.”

Don, climbing away from the final flare, gestured ahead. As he gave a glance backward he saw Garry’s signal of agreement. They must get within easier guarding distance of the Dart at the piling of the boathouse.

As quickly as he saw that the swamp was being surrounded, the Indian might resort to flying for escape. It was not known whether or not he could fly the Dart; but Don surmised that he could. He had managed the helicopter.

When they climbed, steadily going ahead, to a good altitude over the swamp Garry turned his head, observing that Chick saw the same thing that he did as a white, floating flare lighted up the terrain beneath them.

There were two figures visible on the planking of the outer wharf at no pains to conceal themselves.

Instead, they were feverishly unfastening the light airplane, and Don, at Garry’s touch, nodded to show that he already was aware of the fact.

“That Indian can fly!” Don muttered.

He braced his nerves for an unusual effort.

Chick, too, was taut with excitement; his nerves tingled with expectancy; he would have little to do, yet he must be ready to play what part might be possible.

Garry, less excitable, was inclined to feel misgivings.

“What I understand about ship design makes me think this won’t be as much a test of skill as it will be of performance,” he murmured to himself, not having the Gossport apparatus because it had been left in the Dart.

“It is going to be a test between ‘controllability’ and ‘maneuverability’ this time,” Garry added softly.

He realized that airplane design taught the truth that a craft with a certain type of stabilizing fins, and control surfaces, might be very safe and steady in the air, and yet not respond quickly to its stick and rudder, because stability carried to that point might compel a sacrifice of quick answering to control movements.

“That’s the Dragonfly,” he thought.

Light, speedy, almost “touchy” in its easy response to control, the Dart, on the other hand, lacked that safety margin.

The Dragonfly could not go into and come out of aerial “stunt” positions with the same facility that the Dart had. The Dart, though, was so “touchy” that, with its margin of quick answering to controls, quick “stunting” possibilities, it was far less easy to keep in stable flying control.

“We can’t out-maneuver the Dart, if they once get into the air,” Garry decided, “but, then, the Dart isn’t as easy to hold steady as our ’bus is. One thing in our favor will be that Don knows this ship better than John understands the Dart. And—with Don against John,” he thought, whimsically, “it’s a queer thing that our Dragonfly has wings of white and the Dart is lacquered and doped in red.”

He smiled, being of a calm, humorous character.

“White wings or red?” he added. “We’ll have to see what we see!”

Don, almost over the boathouse at the moment, gave a swift look to estimate the progress made by the two beneath him.

“It will take a minute to warm up that engine,” he decided. “We can get into position!” His plan was to make a swoop from a fair altitude, just timed to take the steadier ship across the path of the other, and slightly above it, as it took off.

“The propeller ‘wash’ will throw him out of control too low to catch that touchy Dart,” he told himself. “It will put them down before they get high enough to be hurt badly. I don’t want to be the means of injuring anybody, if I can help it.”

He came around, and gave a quick glance to see the progress of the starting Dart. In the vivid light from a flare that Chick had put over he saw that the red-winged craft was beginning to skip over the water.

It was headed into the wind.

“Why don’t you tell him to dive?” screamed Chick, shivering with excitement and biting at his lip in vexation. Garry had deliberately ignored prodding by his younger comrade.

“Now!” Garry touched Don.

Has calmer nature had held in check his impulse to move too soon.

Exactly in sympathy with Garry’s touch, Don decided that the time to plunge, to rush past and above the Dart, and then to zoom away into the sky for a turn, and an observation, was just right.

Full-gun, with nose lowered, the Dragonfly dashed toward its target, coming up, in a gentle curve, just timed to sweep the turbulent air disturbance of their propeller through the area into which the Dart was just beginning to rise.

They swept with roaring engine across the sheet of water, their own pontoons and wheel-trucks not twenty feet away from the red wings.

Up they zoomed; Don brought the nose around with as sharp a bank as he deemed safe.

All three looked, expecting to see the Dart upset, and its occupant or the pair, if the older Indian had joined his son for escape, struggling in the murky water.

Instead, the Indian, with the cleverness that he had learned, as they discovered at another time, from enlistment at a Navy training school, had cut the gun, settling into the water again.

He had anticipated their maneuver.

Before they could get around and before Don could decide on whether to repeat the dive or to discover some other way of preventing ascent, the Dart strung in a boiling curve, one wingtip pontoon barely touching water to help it swing, and, with the wind, leaving in the water a hot, white seethe of broken wake, slanted sidewise to the breeze and rose.

With skill and quick yielding to control, the Dart swerved around into the wind.

Straight away, climbing rapidly, the small craft went.

After it, gunning up to top speed, went the Dragonfly.

On a level, Don’s speed about equaled the climbing speed of the angle taken by the Indian.

“Will red wings get away from white wings?” murmured Garry.

“Catch him, Don!” screeched Chick, unable to hold his quivering nerves as they made him tremble with eagerness. He felt like a coursing greyhound, urged on a trail but held by a restraining leash, willing to use his own effort, but restrained.

Garry, more controlled, watched.

Along the channel swept the strange chase.

Higher came the Dart. Straight at it, but some hundreds of yards to the rear, tore the Dragonfly, white wings chasing red.

“When he gets on our level,” Don murmured through clenched teeth, “his speed will get him away. If there was anything to do——”

Answering its easy controls as he stopped, surprised, the Dart, almost at their altitude, swerved.

Don, not expecting a turn, kicked rudder nevertheless, to swing on the new flight path.

The Dart, still climbing, made almost a complete, 360 degree turn.

At the half-way point, almost half a circle accomplished, Don went around on wingtip, to get the nose on a new point—he meant to make a direct diagonal across the turn, to try to meet, or forestall, the Dart.

But the smaller ship’s pilot, with gun full open, nose up, seemed almost to leap upward before he reached the stalling point.

He had caused Don to lose the advantage of altitude.

“Clever!” Don conceded, seeing the effect of the ruse. “Now he has only to fly straight away, and we will lose him in twenty miles.”

Chick uttered a cry of surprise.

Garry’s teeth shut tight in dismay.

Don caught his breath

Living up to the name, Dart, the lighter ship went into a wing-over, a maneuver by which, dropping a wing, and thus executing a turn, as it regained flying margin of speed, it exactly reversed the direction of flight.

The Dart, instead of going away from the Dragonfly, had completely altered the conditions: it was coming at the bigger craft.

Just above, and right over the Dragonfly came the other, full-gun.

Don felt the propeller stream tear at his right wing.

There his own ability, coupled with the great steadiness of the ship he handled, saved the situation.

Gently, not forcing or over-controlling, he recovered stability.

“Why!” Don screamed, “he tried to upset—us!”

The pursued had turned pursuer!

Wingtip went down, came up, steadied. Don again had control.

Over went Chick’s next flare, to light up the sky.

They picked up the enemy ship, quickly.

“He’s made an Immelmann turn!” shouted Garry to Don. By that maneuver, half a dive, half a climb, to get the ship to the top of a loop, and then a barrel roll, half-way, to bring it again on its proper keel, again the Dart was in position to swoop.

“He wants to drive us down, I think!” yelled Garry.

Although he could not hear for the roar of their own engine, Don also saw that the greater maneuverability of the other gave him an advantage they had not counted on. Thinking they were to be the hounds, and the Indian the hare, the chums found the conditions reversed. The hare, in his ruddy-winged craft, proposed to hunt down his adversary.

Don, realizing the danger to those with him, desiring no risk of life or limb or property, in the light of the flare, not yet dying, held up both hands in the old war-sign, “Kamerad!” and swiftly caught his stick and throttle again.

In the other ship the arm of the pilot pointed downward.

He did not, however, try to enforce the order to descend by any more swoops: instead, he maneuvered the light craft to a level with, and not fifty feet beyond the Dragonfly.

Don, uncomprehending, puzzled that they were being ordered down, when it had been his expectation to give that order to the other, let the nose drop a trifle, cut the gun, and went on a gentle glide, showing his intention to obey.

The young pilot, red of face, skilful of control, flew along, and as they came almost on a level with the flare, burning still, he turned his head for a glower of triumph toward his victims.

Don, his eyes turned that way to watch the wing separation, saw a look of amazement change the triumphant scowl.

The Indian pilot put out and waved an arm—he pointed toward the airport.

Don nodded, banked, submissively, so astonished and mystified that he could not further plan. Why had that coppery face shown astonishment?

It was a puzzle added to many problems.

With the other craft riding hard, above them, circling swiftly, the captors, now captives, obeyed the signal already given.

Over the edges of the swamps, searchers’ parties showed lights as they realized that the chase had ended, as they supposed. To them it appeared that a ship was being compelled by a skilful adversary to go back. That was true—but it was the pursuing ship that had capitulated.

Hardly had Don run out of speed, and, with Garry and Chick, leaped out to clear the runway, before the lighter Dart came home.

“For the sake of all that’s mysterious!” called Don as the Indian cut his ignition. “We thought you were trying to escape. What made you turn on us?”

“I thought you were the pilot I’m after—and I meant to get the man who stole our treasure chart!” Again the chums were stupefied.