Masters unlocked the handcuffs of the two men in the car. He disposed of his short-wave set in a ditch, for it, too, had batteries which might attract the spheres.

"Get out of the car, Orkins," he ordered.

"Watch him, Masters," Taylor warned. "If he starts yelling, choke him."

"But not too hard," Masters added. "If we're going to be rabbits, human values will change. Men who run into holes will live to eat turnips, those who bare their teeth won't. Orkins might be the forefather of a new race—a helluva race. Come on, Orkins. Get out. Hurry up, Father Abraham, or I'll drag you out."

Orkins, cringing, emerged.

Taylor took charge of Norden, who followed Orkins out of the machine.

"I hate your guts, Norden," he said. "You're a dirty, lousy rat and you ought to be shot. But after all, you're a man. You've courage and I admire it, as much as I hate the way you use it. Overseas there's a war between countries. Here there's another war between humanity and a species of alien monsters. Whether we like it or not, we're allies."

Norden's undershot jaw moved in a grin.

"I know about the spheres, Captain," Norden replied. "I overheard your remarks to Mr. Masters. I've listened to Orkins' babble."

"Will you help us?"

"I will bargain with you."

"For your life? You know I can't do anything about that. I'll do my best—I'll speak a good word at your trial, try to save you from the firing squad, but I'm only a captain. That's all I can do. I haven't the power to do anything more."

"Then I will not help."

"Do you know what we're up against?"

"It looks pretty bad, doesn't it, Captain? But consider my hopeless case."

"We have a chance, Norden. I know, more than any other living man perhaps, what those spheres are. I've seen them close at hand. Any hope of defeating them rests in us, using the meager knowledge I've gained from contact. What happens to your fatherland after the spheres finish on this side of the ocean depends on whether we conquer them, or they exterminate us."

Norden stopped smiling.

"When you put it that way, Captain, how could I refuse?" he asked. "I'll cooperate, not to help you, but to help the fatherland."

The moonlight showed a gleam in Norden's deep-set eyes that Taylor did not like.

They moved to a wooded spot in a nearby field. There was a feeling of semi-security as they settled down to rest under the trees. Orkins' moans of fear were silenced by sleep. Norden sat motionless and Taylor could not tell whether he was asleep or awake. Pember removed his pack and used it for a pillow. Masters snored peacefully on the grass.

Only Taylor remained awake. A sphere floated overhead. Taylor, watching, saw the leaves of the tree stir restlessly as the invisible feelers probed toward the earth.

It was a reddish-orange orb, like the setting sun. Taylor once more got the impression of deeply embedded eyes glowering beneath the shining surface.

Were the eyes an illusion? Did the creatures really have eyes, like those of higher forms of animal life? Illusion or not, the eyes seemed to be there, intense, glaring and savage. They seemed to peer into the depths of Taylor's soul.

Taylor sat motionless, almost positive he was under observation. He expected to feel the jerk of the electric shock of the feeler. Instead, the sphere drifted on. The eyes had not seen.

A moment later flame streaked down from the sphere toward the parking lot. There was a roar as a gasoline tank exploded and flame shot skyward.

"There goes the battery!" Taylor muttered.

The others were roused by the explosion. Orkins sobbed hysterically. Masters, Pember and Norden watched the roaring flame.

"We'll never escape them!" Orkins moaned. "They'll find us sooner or later. They can sense us."

"They're not infallible," Taylor said. "Remember I got away from them in the tunnel." He turned knowingly toward the others. "Perhaps, if we dug a cave—"

"Sure!" said Masters. "It's a good idea."

"Yes, sir!" Pember said with a nod. He pulled his trench tool from his pack and handed it to Orkins. "Maybe you'd like to dig, Mr. Orkins. It'll keep your mind off them things."

Orkins seized the small shovel almost instantly. Taylor half-smiled. He had made the suggestion for Orkins' benefit. The cave probably would never be finished. One deep enough to offer a refuge for five men could hardly be dug in a practical length of time.

Dawn was not far off and the spheres were drifting over the town. Already streets were filled with panic-stricken people. The appearance of the strange balls of fire brought residents from their homes in the middle of the night. Some fled in terror, believing a new type of raider had been invented by the enemy. Others stood watching.

The spheres circled. Taylor watched them, realizing he could do nothing to stop what would happen. There was no way to warn these helpless people that the spheres dealt death in a most sudden and violent form.

Something nagged at Taylor's mind. Why had the sphere gone out when he crept into the tunnel? What had caused it to die? Had the sphere been grounded, trying to reach him under the surface of the earth? Not likely, otherwise the creatures would not be able to attack a man standing on the ground. The bolt, besides, was not electricity, like lightning, but heat, which is not grounded easily.

Where had the spheres come from? They surely were not of this world. On the basis of biological evolution they could not be the children of any life known to science. Had they evolved suddenly, by accident? Some scientists thought all life had grown by accident; the right combination of circumstances had occurred and a chemical action had followed. Had the right combination for the spheres come about as the result of the war and the releasing of untold amounts of energy?

But even if life had begun on earth by accident, all other types had taken ages to develop. These spheres, thinking creatures, could not have evolved overnight.

These seemingly invincible creatures could not have come from this world. Biological development comes through struggle and survival. An invincible creature does not have to worry about its existence—in fact, struggle was necessary to develop an invincible being. These spheres must be from another world. Refugees, perhaps, from another, even more powerful race; or maybe they were seeking a new world to conquer.

One was circling overhead again. The leaves rustled. Taylor thought he heard a choked-off scream. Orkins. He gritted his teeth grimly.

There was only one link of hope in Taylor's chain of thought. There must always be a check to every form of life. Terrestrial plagues of insects were followed suddenly by flocks of birds. In western states an increase in the number of jackrabbits always is a forerunner of an increase in the number of coyotes. But the jackrabbits carried parasites fatal to the coyotes. If man was a rabbit, then perhaps he harbored the check to these creatures of flame.

What check would limit the whispering spheres? No germ, surely. What possible check was there except man's nature? What part of man's nature? That was the answer Taylor wanted to know.

His chain of thought was suddenly interrupted.

Pember was coming on the run. The private saluted the captain.

"Something's wrong, sir! Orkins is throwing a fit."

"Can't you quiet him? The spheres are near."

"Norden held his hand over Orkins' mouth, but it made Orkins worse. I—I think it's serious, sir."

Taylor followed Pember to the place where Orkins had been digging. Norden was there, bending over Orkins, who lay on the ground. Masters, standing behind Norden, shook his head.

"He's dead," Norden said, straightening.

"He was scared to death by the spheres," Masters said. "No one harmed him, except to hold a hand over his mouth. He wasn't choked. He could have breathed through his nostrils—"

"Wait—"

Taylor held up his hand. Something clicked in his brain.

Masters had said something about the spheres that fitted. He said, Maybe you don't have to touch 'em to kill 'em. Figuratively speaking, Orkins hadn't been seriously touched either.

The answer!