"I wish they hadn't made that broadcast," said Lockley. "If there were only monsters involved and they didn't understand English, it would be all right. But with humans helping them, it sets a deadline. If we're going to counter their weapon, they have to use it before we finish the job."

After a moment he said bitterly, "There was a time, right after the last big war, when we had the bomb and n.o.body else did. There couldn't be a cold war then! There were years when we could destroy others and they couldn't have fought back. Now somebody else is in that position.

They can destroy us and we can't do a thing. It'll be that way for a week, or maybe two, or even three. It'll be strange if they don't take advantage of their opportunity."

Jill tried to eat the food Lockley had laid out. She couldn't. She began to cry quietly. Lockley swore at himself for telling her the worst, which it was always his instinct to see. He said urgently, "Hold it! That's the worst that could happen. But it's not the most likely!"

She tried to control her tears.

"We're in a fix, yes!" he said insistently. "It does look like there may be a flock of other s.p.a.ce ship landings within days. But the monsters don't want to kill people. They want a world with people working for them, not dead. They've proved it. They'll avoid ma.s.sacres. They won't let the humans who're their allies destroy the people they want alive and useful."

Jill clenched her fists. "But it would be better to be dead than like that!"

"But wait!" protested Lockley. "We've duplicated the terror beam. Do you think they'll leave it at that? The men who know how to do it will be scattered to a dozen or a hundred places, so they can't possibly all be found, and they'll keep on secretly working until they've made the beams and a protection against them and then something more deadly still! We humans can't be conquered! We'll fight to the end of time!"

"But you yourself," said Jill desperately, "you said there couldn't be a defense against the beam! You said it!"

"I was discouraged," he protested. "I wasn't thinking straight. Look!

With no equipment at all, I found out how to detect the stuff before it was strong enough to paralyze us. You know that. The scientists will have equipment and instruments, and now that they've got the beam they'll be able to try things. They'll do better than I did. They can try heterodyning the beam. They can try for interference effects. They may find something to reflect it, or they can try refraction."

He paused anxiously. She sobbed, once. "But other weapons--"

"There may not be any. And there's bound to be some trick of refraction that'll help. It thins out at the edges now. That's how we get warning of it. It's refracted by ions in the air. That's why it isn't a completely tight beam. Ions in the air act like drops of mist; they refract sunshine and make rainbows after rain. And we got the smell-effect first. That proves there's refraction."

He watched her face. She swallowed. What he'd said was largely without meaning. Actually, it wasn't even right. The evidence so far was that the nerves of smell were more sensitive than the optic nerves or the auditory ones, while nerves to bundles of muscle were less sensitive still. But Lockley wasn't concerned with accuracy just now. He wanted to rea.s.sure Jill.

Then his eyes widened suddenly and he stared past her. He'd been speaking feverishly out of emotion, while a part of his mind stood aside and listened. And that detached part of his mind had heard him say something worth noting.

He stood stock-still for seconds, staring blankly. Then he said very quietly, "You made me think, then. I don't know why I didn't, before.

The terror beam does scatter a little, like a searchlight beam in thin mist. It's scattered by ions, like light by mist-droplets. That's right!"

He stopped, thinking ahead. Jill said challengingly, "Go on!" Again what he'd said had little meaning to her, but she could see that he believed it important.

"Why, a searchlight beam is stopped by a cloud, which is many mist-droplets in one place. It's scattered until it simply doesn't penetrate!" Lockley suddenly seemed indignant at his own failure to see something that had been so obvious all along. "If we could make a cloud of ions, it should stop the terror beam as clouds stop light! We could--"

Again he stopped short, and Jill's expression changed. She looked confident again. She even looked proud as she watched Lockley wrestling with his problem, unconsciously snapping his fingers.

"Vale and I," he said jerkily, "had electronic base-measuring instruments. Some of their elements had to be buried in plastic because otherwise they ionized the air and leaked current like a short. If I had that instrument now--No. I'd have to take the plastic away and it couldn't be done without smashing things."

"What would happen," asked Jill, "if you made what you're thinking about?"

"I might," said Lockley. "I just possibly might make a gadget that would create a cloud of ions around the person who carried it. And it might reflect some of the terror beam and refract the rest so none got through to the man!"

Jill said hopefully, "Then tonight we go into a deserted town and steal the things you need...."

Lockley interrupted in a relieved voice, "No-o-o-o. What I need, I think, is a cheese grater and the pocket radio. And there should be a cheese grater in the house."

He listened at the barn door gap, and then went out. Presently he was back. He had not only a cheese grater but also a nutmeg grater. Both were made of thin sheet metal in which many tiny holes had been punched, so that sharp bits of torn metal stood out to make the grating surface. Lockley knew that sharp points, when charged electrically, make tiny jets of ionized air which will deflect a candle flame. Here there were thousands of such points.

He set to work on the car seat, pushing the pistol with its three remaining bullets out of the way. The pistol was reserved for Jill in case of untoward events, when it would be of little or no practical value.

He operated on the tiny radio with his pocket-knife to establish a circuit which should oscillate when the battery was turned on. There was induction, to raise the voltage at the peaks and troughs of the oscillations. A transistor acted as a valve to make the oscillations repeated surges of current of one sign in the innumerable sharp points of the graters. And there was an effect he did not antic.i.p.ate. The ion-forming points were of minutely different lengths and patterns, so the radiation inevitably accompanying the ion clouds was of minutely varying wave lengths. The consequence of using the two graters was, of course, that rather astonishing peaks of energy manifested themselves in ultra-microscopic packages for a considerable distance from the device. But Lockley did not plan that. It happened because of the materials he had to use in lieu of something better.

When it was finished he told Jill, "I can only check ion production here. If it works, it ought to make a lighter-flame flicker when near the points. If it does that, I'll go up the road to where the trailer-truck stopped. I've a pretty good idea that the road's blocked by a terror beam there."

Absorbed, he threw the switch. And instantly there was a racking, deafening explosion. The pistol on the car seat blew itself to bits, smashing the windshield and ripping the cushion open. The three cartridges in its cylinder had exploded simultaneously.

Lockley seized a pitchfork. He stood savagely, ready for anything.

Powder smoke drifted through the barn. Nothing else happened.

After long, tense moments, Lockley said slowly, "That could be another weapon the monsters have turned on. It's been imagined. They could be using a broadcast or a beam we haven't suspected to disarm the troops of the cordon. They could have a detonator beam that sets off explosives at a distance. It's possible. And if that's what they're turning on they only have to sweep the sky and the bombers aloft will be wiped out."

But there were no sounds other than the slowly diminishing drip of water from the barn roof, and the house eaves, and the few trees in the barnyard.

"Anyhow they've ruined our only weapon," said Lockley coldly. "It would be a detonation beam setting off the cartridges. That would be a perfect protection against atomic bombs, if the chemical explosive that makes them go off could be triggered from a distance. Clever people, these monsters!"

Then he said abruptly, "Come on! It's ten times more necessary for us to get to where somebody can make use of our information!"

"Go where?" asked Jill, shaken once more.

"We take to the woods until dark," said Lockley, "and meanwhile I'll check this supposedly promising gadget--though it looks pretty feeble if the monsters have a detonating beam--against the road blocking beam up yonder. Come on!"

He stuffed his pockets with food. He led the way.

The morning had now arrived. The sun was visible, red at the eastern horizon.

"Walk on the gra.s.s!" commanded Lockley.

There was no point in leaving footprints, though there was no reason to believe the explosion on the car seat had been heard. Lockley, indeed, considered that if the aliens had just used a previously undisclosed weapon, there would be explosions of greater or lesser violence all over the evacuated territory and all other areas within its range. There wouldn't be many farmhouses without a shotgun put away somewhere. There would be shotgun sh.e.l.ls, too. If the aliens had a detonator beam as well as one that produced the terror beam's effects, then all hope of resistance was probably gone.

They crossed to the house and moved alongside it. They went with instinctive furtiveness out of the lane and quickly into the woodland on the farther side. They were soaked almost immediately. Fallen leaves clung to their shoes. Drooping branches smeared them with wetness. Lockley went barely out of sight of the highway and then trudged doggedly in the direction the Wild Life Control trailer-truck had taken. He handed Jill the ribbon of bronze that had been the mainspring of his watch.

"We might pick up the beam from the wetness underfoot," he said, "but we'll play it safe and use this too."

They went on for a long way. Lockley fumed, "I don't like this! We ought to be there--"

"I think," said Jill, "I smell it."

"I'll try it," said Lockley.

He detected the jungle smell and its concomitant revolting odors. He led Jill back.

"Wait here, by this big tree stump. I'll be able to find you and you're safe enough from the beam."

He turned away. Jill said pleadingly, "Please be careful!"

"A little while ago," he told her gloomily, "I felt that I had too much useful information to take any chances with my life, let alone yours. I'm not so sure of my importance now. But I think you still need somebody else around."

"I do!" said Jill. "And you know it! I'd much rather--"