takes him farther away from his main source
of power, the Solar System's radiation. He could collect power anywhere
in space, you know, but the best place to collect it is near large
radiant bodies."

Russ continued to crouch over the dial, begrudging every backward
flicker of the needle.

This was the last play, the final hand. If they could drag Craven and
his ship away from the Solar System, maroon him deep in space, far
removed from any source of radiation, they would win, for they could go
back and finish the work of smashing Interplanetary.

But if Craven won--if he could halt their mad dash for space, if he
could shake free--they'd never have another chance. He would be studying
that field they had wrapped around him, be ready for it next time, might
even develop one like it and use it on the _Invincible_. If Craven could
win his way back to the Sun, he would be stronger than they were, could
top them in power, shatter all their plans, and once again the worlds
would bow to Interplanetary and Spencer Chambers.

Russ watched the meter. The speed was little more than ten miles a
second now and dropping rapidly. He sat motionless, hunched, sucking at
his dead pipe, listening to the thrumming of the generators.

* * * * *

"If we only had a margin," he groaned. "If we just had a few more
horsepower. Just a few. But we're wide open. Every engine is developing
everything it can!"

Greg tapped him on the shoulder, gently. Russ turned his head and looked
into the face of his friend, a face as bleak as ever, but with a hint of
smile in the corners of the eyes.

"Why not let Jupiter help us?" he asked. "He could be a lot of help."

Russ stared for a moment, uncomprehending. Then with a sob of gladness
he reached out a hand, shoved over a lever. Mirrors of anti-entropy
shifted, assumed different angles, and the _Invincible_ sheered off.
They were no longer retreating directly from the Sun, but at an angle
quartering off across the Solar System.

Greg grinned. "We're falling behind Jupiter now. Letting Jupiter run
away from us as he circles his orbit, following the Sun. Adds miles per
second to our velocity of retreat, even if it doesn't show on the dial."

The cosmic tug of war went on, grimly--two ships straining, fighting
each other, one seeking to escape, the other straining to snake the
second ship into the maw of open, hostile space.

The speed was down to five miles a secon