Chick, shouting, appeared at the end of a path, with the control chief, and guided by Doc, who knew the swamp trails.

“There’s somebody swimming!” he screamed.

Don paid no attention.

“Watch him!” he called, and then, as the launch came close to the Dart, caught a wing and clambered into the cockpit.

Garry, who took the wheel, ran forward again until he could revolve the small, fast airplane’s propeller: as his yell was answered by Don’s “contact!” he swerved aside, saw the huge blades begin to swing, heard the roar of the engine, and hastened to get his launch out of the path of the oncoming Dart.

Swiftly gathering speed, with sharp spurts of the gun to clear his choked cylinders, Don lifted his speedy ship into the air, soaring over Garry’s head as the latter, nosing in at the path end, took on Chick.

Up went Don, climbing in as speedy and steep a banked ascent as he dared with a recently stopped power plant to consider. He dared not force the engine until it was again at fullest, safest operating temperature.

The helicopter, rising almost straight up, had an advantage. But Don did not let that concern him. His teeth were tight, clenched, with determination wrinkling his eye-corners.

The Demon had gone too far. Evidently he had meant to lure them in the airplane, only to “finish them off” in some fashion. Garry’s unexpected appearance in the launch had upset those purposes. The Demon, taking advantage of the new chase, getting back to his craft, meant to escape, to lie hidden somewhere, ready to visit more of his menacing attacks on innocent folk.

“Not if I can keep my head,” Don muttered.