Even as he spoke the flyer gave a lurch which nearly threw me off my seat and which sent Jim sprawling on the floor. With a white face he leaped to the control board and pulled the lever controlling our one working stern motor to full power. For a moment the ship moved upward and then came to a dead stop, although the motor still roared at full speed.
"Can't you see anything, Pete?" cried Jim as he threw our second stern motor into gear.
Again the ship moved upward for a few feet and then stopped. I swung the searchlights frantically in all directions, but five of the screens remained blank and the sixth showed only the ground below us.
"Not a thing," I replied.
"Something ought to show," he muttered, and suddenly shut off both motors. The flyer gave a sickening lurch toward the ground, but we fell only a hundred yards before our motion stopped. We hung suspended in the air with no motors working. Jim joined me at the screens and we swung the lights rapidly without success.
"Look, Pete!" Jim cried hoarsely.
My gaze followed his pointing finger and I saw the door of our flyer springing out as though some force from the outside were trying to wrench it open. The pull ceased for an instant, then came again; the sturdy latches burst and the door was torn from its hinges. Jim swung one of the searchlights until the beam was at right angles to the hull of the flyer and pressed the gun button. A crash filled the confined space of the flyer as a one-pounder radite shell tore out into space.
"They're there but still invisible," he exclaimed as he shifted the direction of the gun and fired again. "I am shooting by guess-work, but I might score a hit."
He changed the direction of the gun again, but before he could press the button he was lifted into the air and drawn rapidly toward the open door.