"Climb aboard quickly!"
Jack needed no urging and a moment later the two boys were ready for flight. And then, suddenly, there was the crack of a revolver behind them and a bullet flew close to Jack's ear.
The German leader had recovered consciousness, and springing to his feet, dashed to the water's edge and fired point blank at the machine. Fortunately, in his excitement his aim was poor and he missed. Before he could fire again, Frank wheeled about and his revolver spoke sharply.
The German threw up his arms, and with a gasp, pitched headlong into the sea.
But the sounds of the two shots had aroused the sleeping camp. Wild cries came from the shore, followed by heavy footfalls as the Germans rushed toward the water.
"Hurry, Frank!" cried Jack.
As lightly as a fairy the hydroplane skimmed over the water; then went soaring in the air. Frank gave a loud cheer.
"Safe!" he exclaimed.
But the lad was wrong.
From on shore came a chorus of angry cries and imprecations. Hastily the Germans made a rush for their aeroplanes to give chase. None would move. Followed more cries and angry shouts.