round us, but no image on the screens rewarded
us.

"Doggone it, they must have left here in a hurry," grumbled Jim.

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.

"Shoot, Pete!" he shouted. "Shoot and keep on shooting--it's your only
chance!"

I turned to the knobs controlling the guns and lights, but, before I
could make a move, something hard and cold grasped me about the middle
and I was lifted into the air and drawn toward the open door after Jim.
I tore at the thing holding me with my hands, but it was a smooth round
thing like a two-inch thick wire, and I could get no grip on it to
loosen it. Out through the