In less than half a minute the man who had once conquered a planet was reduced to a steaming mound of brownish paste. As it sank to the floor of the case, it touched a layer of coarse yellow powder sprinkled there; and it was this that caused the vapor. In a moment the room was filled with the haze of it; luckily, the doctor's apparatus worked well.

And thus it came about that, within five minutes from being exposed to the air of the sky-car, that whole immense bulk, chair and all, had vanished. The powder had turned it to vapor, and the purifying chemicals had sucked it up. Nothing was left save a heap of smoking, grayish ashes in the center of the broken glass.

Van Emmon's fingers relaxed their grip. He stirred to action, and turned briskly to Smith.

"Here! Help me with this thing!"

Between them they got the remains of the cabinet, with its gruesome load, into the vestibule. As for the doctor, he was bending over Jackson's still unconscious form. When he saw what the others were doing, he gave a great sigh of relief.

"Good!" He helped them close the door. "Let's get away from this damned place!"

The outer door was opened. At the same time Smith started the machinery; and as the sky-car shot away from the ground he tilted it slightly, so that the contents of the vestibule was slid into space. Down it fell like so much lead.

The doctor glanced through a nearby window, and his face brightened as he made out the distant gleam of another planet. He watched the receding surface of Mercury with positive delight.

"Nice place to get away from," he commented. "And now, my friends, for Venus, and then—home!"