He stabbed viciously at the keys on the board and once again the shrill howl of the engines came from the rear of the ship. A lance of red splashed out across s.p.a.ce and touched the other ship. Again s.p.a.ce was lit, this time with a crimson glow.

Russ shook his head. "Nothing doing."

Greg sat down and looked at Russ. "Funny thing about this. They just sat there and let us throw two charges at them, took everything we gave them and never tried to hand it back."

"Maybe they haven't anything to hand us," Russ suggested hopefully.

"They must have. Craven wouldn't take to s.p.a.ce with just a purely defensive weapon. He knew we'd find him and he'd have a fight on his hands."

Russ found his pipe was dead. Snapping his lighter, he applied flame to the blackened tobacco. Walking slowly to the wall cabinet, he lifted two other boxes out, set them on the table and took from them two other mechanical shadows. He turned them on and leaned close, watching the spinning dials, the quivering needles.

"Greg," he whispered, "Chambers and Stutsman are there in that ship with Craven! Look, their shadows register identical with the one that spotted Craven."

"I suspected as much," Greg replied. "We got the whole pack cornered out here. If we can just get rid of them, the whole war would be won in one stroke."

Russ lifted a stricken face from the row of tiny mechanisms. "This is our big chance. We may never get it again. The next hour could decide who is going to win."

Greg rose from the chair and stood before the control board. Grimly he punched a series of keys. The engines howled again. Greg twisted a dial and the howl rose into a shrill scream.

From the _Invincible_ another beam lashed out ... another and another.

s.p.a.ce was speared with beam after beam hurtling from the great ship.

Swiftly the beams went through the range of radiation, through radio and short radio, infra-red, visible light, ultra-violet, X-ray, the gammas and the cosmics--a terrific flood of billions of horsepower.

Craven's ship buckled and careened under the lashing impacts of the bombardment, but it seemed unhurt!

Greg's face was bleaker than usual as he turned from the board to look at Russ.

"We've used everything we have," he said, "and he's stopped them all. We can't touch him."

Russ shivered. The control room suddenly seemed chilly with a frightening kind of cold.

"He's carrying photo-cells and several thousand tons of acc.u.mulator stacks. Not much power left in them. He could pour a billion horsepower into them for hours and still have room for more."

Greg nodded wearily. "All we've been doing is feeding him."

The engines were humming quietly now, singing the low song of power held in leash.

But then they screamed like a buzz saw biting into an iron-hard stick of white oak. Screamed in a single, frightful agony as they threw into the protecting wall that enclosed the _Invincible_ all the power they could develop.

The air of the ship was instantaneously charged with a hazy, bluish glow, and the sharp, stinging odor of ozone filled the ship.

Outside, an enormous burst of blue-white flame splashed and spattered around the _Invincible_. Living lightning played in solid, snapping sheets around the vision port and ran in trickling blazing fire across the plates.

Russ cried out and backed away, holding his arm before his eyes. It was as if he had looked into a nova of energy exploding before his eyes.

In the instant the scream died and the splash of terrific fire had vanished. Only a rapidly dying glow remained.

"What was it?" asked Russ dazedly. "What happened? Ten engines every one of them capable of over five billion horsepower and every one of them screaming!"

"Craven," said Greg grimly. "He let us have everything he had. He simply drained his acc.u.mulator stacks and threw it all into our face. But he's done now. That was his only shot. He'll have to build up power now and that will take a while. But we couldn't have taken much more."

"Stalemate," said Russ. "We can't hurt him, he can't hurt us."

"Not by a d.a.m.n sight," declared Greg. "I still have a trick or two in mind."

He tried them. From the _Invincible_ a fifty-billion-horsepower bolt of living light and fire sprang out as all ten engines thundered with an insane voice that racked the ship.

Fireworks exploded in s.p.a.ce when the bolt struck Craven's ship. Screen after screen exploded in glittering, flaming sparks, but the ship rode the lashing charge, finally halted the thrust of power. The beam glowed faintly, died out.

Perspiration streamed down Greg's face as he bent over a calculator and constructed the formula for a magnetic field. He sent out a field of such unimaginable intensity that it would have drawn any beryl-steel within a mile of it into a hard, compact ma.s.s. Even the _Invincible_, a hundred miles away, lurched under the strain. But Craven's ship, after the first wild jerk, did not move. A curious soft glow spread out from the ship, veered sharply and disappeared in the magnetic field.

Greg swore softly. "He's cutting it down as fast as I try to build it up," he explained, "and I can't move it any nearer."

From Craven's ship lashed out another thunderbolt and once again the engines screamed in terrible unison as they poured power into the ship's triple screen. The first screen stopped all material things. The second stopped radiations by refracting them into the fourth dimension. The third shield was akin to the anti-entropy field, which stopped all matter ... and yet the ten engines bellowed like things insane as Craven struck with flaming bolts, utilizing the power he had absorbed from the fifty billion horsepower Greg had thrown at him.

There was anger in Greg Manning's face ... a terrible anger. His fists knotted and he shook them at the gleaming ship that lay far down near Jupiter.

"I've got one trick left," he shouted, almost as if he expected Craven to hear. "Just one trick. d.a.m.n you, see if you can stop this one!"

He set up the pattern on the board and punched the activating lever. The ten engines thrummed with power. Then the howling died away.

Four times they screamed and four times they ebbed into a gentle hum.

"Get on the navigation controls!" yelled Greg. "Be ready to give the ship all you've got."

Greg leaped for the control chair, grasped the acceleration lever.

"Now," growled Greg, "look out, Craven, we're coming at you!"

Greg, teeth gritted, slammed the acceleration over.

Suddenly all s.p.a.ce wrenched horribly with a nauseating, terrible thud that seemed to strain at the very anchors of the Universe.

_CHAPTER EIGHTEEN_

Jupiter and the Jovian worlds leaped suddenly backward, turned swiftly green, then blue, and faded in an instant into violet. The Sun spun crazily through s.p.a.ce, retreating, dimming to a tiny ruby-tinted star.

The giant generators in the _Invincible_ hummed louder now, continually louder, a steel-throated roar that trembled through every plate, through every girder, through every bit of metal in the ship.