Instantly the situation became clear to the Sky Patrol.

Having heard their own engine, the pilot of the seaplane had decided to risk a dash out of the fog and to try to escape.

Their own airplane had been headed south, down the coast.

When they climbed above the lower shoreward mist the cry from Sandy drew their attention to the seaplane, even higher than they were, and going fast across the narrow end of the island.

“Now we can catch them and ride them down!” exulted Dick.

Jeff dropped a wing sharply—kicking rudder at the same time. Onto the trail swung their craft. Righting it Jeff gave the engine all it would take, climbing.

“They’re getting ahead—getting away from us!” cried Sandy.
51

Larry, more conversant with flying tactics, decided that Jeff meant to get to a higher level than they occupied, to outclimb the less flexible seaplane, so that he could swoop upon it with the advantage of elevation to help him overtake it.

Into the thousands their altimeter swung its indicator.

Three thousand feet! Another five hundred! Four thousand!

“Now we must be higher than they are!” Larry muttered. “Jeff—for crickety-Christmas’ sake—catch them!”

Jeff leveled and their engine roared. In a quartering course, evidently making in an airline for some point on the Connecticut side of Long Island Sound, the seaplane held its way.

Gaining in a very flat descent, calculated, as Sandy could see, to bring them either alongside or—if fortune favored them—onto the tail of the other craft, Jeff drew closer.

The seconds slipped by. The North Shore was almost under them.

Swiftly the distance closed up between the racing flyers.

“They’re diving!” cried Sandy.

“Something’s gone wrong!” Dick yelled. “She’s out of control!”
52

The seaplane sheered to one side in a violent slip as her pilot evidently tried to bank and kick rudder and lost control.

The seaplane wavered, caught itself in a steadier line. In the pursuing airplane three youthful faces grew intent.

What was wrong?

“She’s diving!” screamed Sandy.

“Something has happened!” decided Larry.

Down, almost like a hawk falling to its prey, the seaplane went through the still air.

“Somebody’s on the wing—he’s jumping clear!” shouted Dick.

Trembling with excitement Larry caught up the binoculars. They were still too far behind for clear vision unaided by glasses.

“He has that life preserver in one hand—there he goes!” cried Dick.

Silhouetted against the northern blue of the sky, with a tiny white circle showing sharply in the sunlight, the leaping person fell clear of the diving seaplane, while Larry, shaking with excitement, tried to focus his glasses and train them on the falling object.

“He’s harnessed to a parachute—there goes the ripcord!” Sandy would have leaped to his feet but for his restraining safety belt.

“There goes the ’chute!” Dick was equally thrilled.
53

The parachute opened.

“The life preserver snapped out of his hand!” Larry muttered, giving up his effort to locate the moving objects in the glass and using his unaided eyes to view the tragedy—or whatever it would prove to be.

The life preserver was jerked away by the jar when the parachute arrested the fall sharply, making it impossible for a handgrip to retain the rope of the swiftly plunging white circle.

“Why doesn’t the other one jump clear!” Dick’s heart seemed to be tearing to get out through his tightening throat. Which one was under the parachute? Which stayed in the falling seaplane—and why?

An arm of mist, swinging far over the land, intervened between their vision and the shore line.

Into it, hidden from sight, the seaplane flashed.

Through its concealing murk flicked the tiny round object of mystery.

More deliberately, settling down, first the hanging bulk of the unknown man, then the spreading folds of the parachute drifted into mist—and mystery.

The chase was ended.

But the mystery had hardly begun!