The truck came up.
"Come on, Doctor," cried McCready. "Hurry up. We'll take the battery out of this truck and get our plane going."
"Oh, clever!" cried Dr. Bird admiringly. "Load that gun while I get Feodrovna, Carnesy. We'll get away safely yet."
The truck rolled up to the plane and stopped. While Carnes transferred the prisoner and the guns to the plane, the lieutenant and Dr. Bird ripped up the floor boards of the truck and exposed the battery. It was a matter of moments to detach it and carry it to the plane. It would not fit in place but they anchored it in place with wire.
"You'd better hurry," cried Carnes. "Here come a couple more trucks over the plain."
"That'll do, Doctor," said McCready. "Get on the prop and we'll see if the old puddle jumper will take off."
Dr. Bird ran to the propeller.
"Ready!" he cried.
"Contact!" snapped McCready.
The plane motor roared into life. The ship moved slowly forward as Dr. Bird climbed on board. Toward the oncoming trucks they rushed across the plain. A crash seemed imminent. In the nick of time McCready pulled back on his joystick and the plane rose gracefully into the air, clearing the leading truck by inches. The truck halted and hastily mounted a machine gun.