Jack, with his feet wide apart and arms extended, braced himself to receive the shock; and when it came he was ready. Frank, in the meantime, sank down in the plane almost unconscious, for one of the Germans had all but choked the life from him.
As the first German sprang, Jack met him with a straight right hand blow to the face and the man reeled back. The second, seeing the fate of his companion, dived for Jack's legs and seized them, pulling the lad down.
Jack felt out with his left hand and encircled the German's neck. Then he squeezed. The German gasped for breath as his wind was shut off. His hand searched his belt and presently flashed aloft with a knife. Jack saw it. Releasing his hold on the man's throat, he seized the knife arm with his left hand and twisted sharply, at the same time driving his right fist into the man's face.
There was a sharp snap and a cry of pain. The knife fell clattering to the deck of the plane. Jack, very angry, rose to his feet, stooped over, and picking up the German as though he had been a child, heaved him overboard.
"So much for you!" he muttered.
He stepped across the body of the second German to Frank's side and stooped over him. Gently he raised his chum's head to his knee.
Frank's eyelids flickered and directly he opened his eyes.
"How do you feel, old man?" asked Jack.
Frank struggled free from his chum's grip and sat up. He shook his head once or twice and then rose to his feet.
"I'll be all right in—Look out!" he broke off suddenly.