“Somebody had to be in that hydroplane,” Sandy mused. “They were there to switch on the light, to turn the boat, and to set it on the new course!”

Quickly he peered to the side and back, downward at the water in the place where the first landing flare had settled into the water.

Just a little closer to their position, should have been the spot where the clever miscreant might have abandoned the boat.

Sooner than that, Sandy guessed, the unknown person could not have quit the hydroplane: otherwise the turning from shore would have continued and the hydroplane, instead of proceeding in a straight course away from land, would have swept in a wide circle, round and round.

“There’s no life preserver in the boat either—so that’s what the mystery man used to swim away with—Mr. Everdail’s jewels!” he added.
161

Straining his eyes, he peered, looking for a bobbing head, a round white object supporting a body, as the flare died. Dick, arguing in much the same fashion, stared from the other side of the fuselage and gave a shout of elation.

“There!”

His arm pointed.

Sandy prodded Jeff, and quickly the pilot, much recovered, gave Larry his instructions.

“Nose up—we’re getting too low. Right! Now a right bank—not too steep. Don’t get excited. That-there lad in the hydroplane headed her outbound and then took to the water. Now we’re heading in—steady with that-there rudder—don’t try to jam her around—now she’s all right. Level off and hold her as she is.”

Larry obeyed all instructions, doing the work as Jeff gave the order. Larry was rapidly growing sure of his ability.

He fought down the excitement that wanted to express itself in hasty manipulation of his controls and kept a steady hand and a cool brain.

Dick, scribbling hurriedly, passed a note to Sandy, who read it in the light of the flash, and then passed both paper and light to Jeff.
162

Dick, recalling a wide, spacious cement-floored parking space at a nearby bathing resort, had suggested “setting down” there. As he read the note Jeff shook his head.

“Dangerous trying to land there!” was the note Jeff passed back as Larry flew the airplane at just above stalling speed toward the shore. Dick agreed. After all, there might be automobiles in the parking lines, and the light might be bad for Larry. Even using a power-stall by which, with the engine going and a flat gliding angle, the airplane could settle gradually closer until it took the ground with hardly a jar, the maneuver would not be safe, Dick admitted.

“Here comes another ’plane!” Sandy called out, taking the flashlamp from Jeff again as the older pilot handed it back. “He’s flying right after us.”

They all located the drone of the other engine.

“Steady, Larry!” Jeff cautioned. “Hold as you are. That-there is our amphibian—and I reckon the boss is doing the control job.”

The amphibian, as they made out its pontoon understructure, came fairly close alongside. Its speed was almost identical with their own and at first all four occupants of the land crate wondered who was in it, and why.

“Signaling!” cried Larry, cutting the gun and turning to observe.
163

“All right, buddy,” admonished Jeff. “Stick to your job. Sandy or Dick will read the dots and dashes—if he’s using Morse code——”

“He is spelling out something with his flashlight,” Sandy decided, as he saw short flickers and longer dashes of light while the amphibian kept a course within close range but at safe wing distance.

“I’ve got it!” Dick passed forward his paper.

“‘G-i-v-e r-e-p-o-r-t,’” Sandy read, and as he handed Jeff the note, Sandy, using his own light, sent back the Morse code answer:

“Man swimming ashore with life belt.”

Then, with the beam directed in the path the mysterious unknown must have taken, he tried to show the occupant of the amphibian what he meant.

Evidently the endeavor succeeded, for the amphibian dived, and took to the water, while Larry, directed by Jeff, swept around in a circle out of range if the amphibian rose unexpectedly, but within visual range of its maneuvers.

Watching intently, his comrades saw that the amphibian kept on toward shore in a taxiing course on the water surface.

A shout greeted the advent of an automobile on a shore drive. As it swung around a curve, close to the water, its ............