Greg looked. There was no hole in the end of the barrel. "This thing's crazy," he said.

"And then some," Johnny said. "You haven't had this out of the case since you took it from the pack?"

"Just once," said Tom. "And I put it right back. I hardly looked at it.

Look, maybe it's just a new model Dad got."

"It's no new model. I'm not even sure it's a gun," Johnny said. "Doesn't _feel_ like a gun."

"What happens when you push the stud here?" Greg asked.

Johnny licked his lips nervously. "Try it," he said.

Greg leveled the thing at the rear wall of the lounge and pressed the stud. There was a sharp buzzing sound, and a blinding flash of blue light against the wall. It looked for all the world like the flash of a live power line shorting out. They squinted at the flash, rubbed their eyes....

And stared at the wall. Or at what was left of the wall, because most of the wall was gone. The metal had bellied out in a six-foot hole into the storage hold beyond....

Johnny Coombs whistled. "This thing did _that_?" he whispered.

"It must have...."

"But there's no gun ever made that could do that." He walked over to the hole in the wall. "That's half-inch steel plate. There's no way to pack that kind of energy into a hand gun."

They stared at the innocent-looking weapon in Greg's hand. "Whatever it is, Dad must have put it in the gun-case."

"Yes, he must have," Johnny said.

"Well, don't you see what that means? _Dad must have found it somewhere_. Somewhere out here in the Belt ... a gun that no man could have made...."

He took the weapon, ran his finger along the gleaming barrel. "I wonder," he said, "what else Dad might have found out there."

Somewhere below them they heard a hatch clang shut, and even deeper in the ship generator motors began throbbing in a steady even rhythm. In the silence of the lounge they could hear their own breathing, and outside a thousand tiny sounds of the ship's activity were audible.

But now they had attention only for the odd-shaped piece of metal in Greg's hand, and for the hole that gaped in the wall.

"You think that _this_ was what Dad found?" Greg said. "The Big Strike he told Johnny about?"

"It must be part of it," Tom said.

"But what is it? And where did it come from? It doesn't make sense,"

Greg protested.

"It doesn't make sense the way we've been looking at it," Tom said. "All we've found was some gobbledegook in Dad's private log to tell us what he found ... but it couldn't have been a vein of ore, or Tawney's men would have unearthed it. It had to be something else. Something that was so big and important that Dad didn't even dare let Johnny in on it."

"Yes, that's been the craziest part of it, to me," Johnny said. "I've done a lot of mining with your Dad. If he'd hit rich ore, he would have taken me out there to mine it with him. But he didn't. He said it was something he had to work on alone for a while, and he sent me back."

"As if he'd found something that scared him," Tom said, "or something that he didn't understand. He was _afraid_ to tell anybody. And whatever he found, he managed to hide it somewhere, so that n.o.body would find it...."

"Then why didn't he hide this part of it, too?" Greg said.

"Maybe to be sure there was some trace left, if anything happened to him," Tom said.

They were silent for a moment. The only sound was the stertorous breathing of the unconscious guard. "Well," Greg said finally, "I have to admit it makes sense. It makes other things add up better, too. Dad was no fool, he must have known that Tawney was onto something. And Dad would never have risked his life for an ore strike. He'd either have made a deal with Tawney or let him hijack the lode, if that was all there was to it. But there's still one big question ... where did he hide what he found? And we aren't going to find the answer here." He walked over to the hole in the wall.

"Made quite a mess of it, didn't it?" Johnny said.

"Looks like it. I wonder what that thing would do to a ship's generator plant." He turned to Johnny. "We haven't much time. With this thing, we could tear this ship apart, leave them so confused they'll never know what broke loose. And if we could get that gun back to Major Briarton, he'd have to listen to us, and get the U.N. Patrol into the search...."

They had been so intent on their talking that they did not hear the footsteps in the corridor until the door swung open. It was another guard, the one who had departed with Tawney. He stopped short, blinking at his companion on the floor, and then at the gaping hole in the wall.

When he saw the twins, side by side, his jaw sagged and a strangled sound came from his throat.

Then Johnny grabbed his arm, jerked him into the lounge, and slammed the hatch shut. Greg pulled the stunner from his holster and tossed it to Tom. The guard let out a roar, twisted free, and met Johnny's fist as he came around. He sagged at the knees and slid to the floor beside the other guard. "All right," Johnny said, "we've dealt the cards, now we'd better play the hand. Tom, you first."

Tom pulled the ventilator grill down, and climbed up into the shaft.

Greg followed, with Johnny at his heels, pulling the grill back up into place from the inside. They waited for a moment, but there was no sound from the lounge.

"All right," Johnny said breathlessly. "Let's move."

Swiftly they started down the dark tunnel.

11. The Haunted Ship

They did not pause, even to catch their breath, for the first twenty minutes as Tom led them swiftly and silently down through the maze of corridors and chutes that made up the ventilation system of the huge ship. Greg lost his bearing completely in the first twenty seconds; each time his brother paused at a junction of tubes, he felt a wave of panic rise up in his throat ... suppose they lost themselves in here! He heard Johnny's trousers flapping behind him, saw Tom's figure flit past another grill up ahead, and plunged doggedly on.

It was amazingly hard to move quietly. Even in stocking feet they made a soft thud with each footfall.

But there was no sign of detection, no sound of alarm. Finally they came out into a large shaft which allowed them to stand upright, and they stopped to catch their breath.

"Main tube to the living quarters," Tom said when they had caught up to him. "Joins with the lower-level tube by a series of chutes. We've actually been circ.u.mnavigating the ship ... I wanted to get as far away from that lounge compartment as possible, in case they check up on you right away."

"We can't have much time," Johnny said. "That second guard must have been coming to relieve the other, and when the first one doesn't report back, they'll smell something fishy."

They talked it over for a moment. Johnny had been careful to leave the hatchway into the corridor ajar before he climbed into the ventilator shaft, and then he had pulled the shaft snugly into place behind him.

Anyone who came would find two unconscious guards, a burnt-out hole in the wall, and the door unlocked.

"We'll hope that he takes things at face value, and a.s.sumes we're at large in the ship somewhere, for a while at least," Johnny said. "That hole in the wall is going to set them back a couple of steps, too."

"But they'll sound the alarm, at least," Tom said.

"You bet they will! They'll have every man on the crew shaking down the ship for us. But they may not think of the ventilators until they can't find us anywhere else."