The sphere pulsed again. But this time no flaming whip sprang from its surface. There was a single flash. For an instant Taylor caught a glimpse of bestial eyes, looking angrily at him from the center of the flash. Then there was nothing. He was in the darkness of a tunnel. Even the charred embers of the wooden trap door above him seemed dimmed by a cloud of dust.

The sphere had simply exploded.

Taylor had no time to analyze the situation. His hands groped along the side of the tunnel, the one Norden had used to enter the plant on his spying expeditions. Taylor crawled slowly, feeling his way. It seemed eternity until at last he reached the end of the passage and felt the trap door overhead.

A minute later he rejoined the others, huddled in darkness outside the gate.

"The searchlight went out," Masters explained. "Something wrong with the power, I guess."

"I know what it was," Taylor said gruffly. He turned to the disarmed sentry. "Has anyone come out of here since the factory stopped working?"

"Nobody but him, sir," the soldier said, jerking his thumb at the sobbing man huddled against Norden. "He said his name was Orkins—Jim Orkins. He works in the warehouse. But you can't tell anything about the rest o' what he says. He just babbles, sir. Something about livin' lightnin' and balls of fire. He ain't drunk, sir, so he must be crazy."

"Help him get up," Taylor ordered. "Masters, you take charge of Norden. We're going back to the car."

"Excuse me, sir," the sentry said, hesitantly. "But that's against orders. I can't leave. I'm to guard this gate, sir."

"Your orders are canceled," the captain said.

"If I desert my post, it's court martial," the sentry explained. "How do I know you aren't a spy? Captains don't go around making privates break the orders of the day. If you've got business in the plant, why was I told to keep everyone out? Why didn't they tell me to pass Captain Taylor? I got a duty here and I'll do it if it kills me. So help me, sir. Sergeant o' the guard!"

The echo of the sentry's bellow rattled against the bleak factory buildings. A sphere bobbed up through the hole in the roof. Orkins opened his mouth to scream, but Norden clapped his hand over the man's lips, choking him off.

"Quiet!" Taylor ordered hoarsely. He addressed the sentry: "See that thing? It means death to you, to all of us if it finds us. The sergeant of the guard, probably all of the other sentries are dead. Every workman in the plant is dead. Somehow we were missed. The searchlight power went off before they found this post, I suppose. Now then, all of you follow Masters back to the car. I'll bring up the rear."

"I won't leave," the sentry said, stubbornly.

Masters stepped forward and put his pistol against the soldier's back.

"You'll go," he said. "Maybe this ain't regulation, but neither are the spheres."

The stubby little secret service man pushed the soldier ahead of him. The sentry marched with his hands in the air.

Drawing his own pistol, Taylor turned to Norden.

"Help Orkins to the car," he said.

Norden drew himself up stiffly.

"Go ahead and shoot," he said. "It'll save the firing squad some trouble."

Taylor took one step forward. Norden faced him unflinchingly. Taylor's hand shot out, caught Norden's coat and threw him after Masters.

"Don't leave me alone!" Orkins cried, crawling after Norden and clasping him about the legs. Norden kicked him aside.

"Keep moving!" Taylor ordered Norden, who had halted.

Norden did not move.

Taylor swung his fist. The blow connected and the officer caught the falling man, swung him over his shoulder, then turned to the cringing Orkins.

"If you don't want to be left here alone, follow us," he said.

Orkins suddenly regained his ability to use his muscles.

Masters, watching over his shoulder, chuckled. There was a faint wink of one eye visible in the moonlight.

"Kinda screwy, ain't he?" he said, jerking his head in Orkins' direction.

"I don't know that I blame him, much," Taylor said. "Look at the plant."

Over the roof and the smokestacks floated the yellowish-red ball of fire. Another sphere was emerging from the hole in the roof.

"What are they? A new kind of bomb?" Masters asked.

"Norden's bomb never had a chance. Compared with what actually happened in there, a bomb would have been a picnic. There's not a living person left in the whole place."

"Not a—hold on there, Cap! Do you know how many were working?"

"They're all dead," Taylor said. Briefly he outlined what he had seen in the plant.

"Norden, the blankety-blank!" Masters swore. "Shooting's too good for him."

"This isn't connected with the war—at least not directly. It's something else, Masters. What, I don't know yet, but I'm beginning to think that it's something the human race has never met before. Those spheres have killed a couple of hundred workers with bolts of energy—"

"I'm no scientist, captain."

"That's the best I can describe this force, Masters. I might call it heat-bolts, but it's probably partly electric and partly heat, not entirely either. You see, Masters, heat is energy, just like electricity and light. The energy these spheres shoot out is a mixture of energies. We can imagine a spark of electricity shooting out and striking a man like a bolt of lightning, but it's hard to visualize heat behaving that way."

"Say, mister," the sentry interrupted, "my arms are getting tired."

"Okay, buddy," Masters replied. "If I let you put your arms down, will you behave like a nice little boy?"

"I'll be a perfect angel," the sentry said, lowering his arms.

"You'll be an angel if you aren't, too," Masters added.

"What's your name, soldier?" Taylor asked the sentry.

"Private Pember, sir. Company A, 110th infantry—"

"All right, Private Pember, you can carry this fellow."

Taylor shifted the faintly stirring Norden to the shoulders of the soldier.

"If it will make you feel any easier, Pember," the captain went on, "I can assure you that exigencies demanded your removal from your post. Your life was in danger and you could do no good by remaining there. In fact, there was nothing left to guard. You can do more good for your country by coming with us."

"Yes, sir," Pember said. "I guess you are right, captain."

"You're a good soldier, Pember," Taylor went on. "A situation like this is unique. It demands use of individual initiative, rather than blind obedience to orders. Do you understand?"

"Yes, sir," Pember said, adjusting the burden on his shoulder.

They reached the car.

A dozen of the orange-red globes now floated above the plant. They were circling slowly, in widening arcs, toward the limits of the factory grounds.

"Searching for human beings," Taylor decided, watching them.

Orkins clutched Taylor's coat tails.

"They're coming out!" he cried. "There's hell to pay."

Taylor took Orkins' arm and forced him down on the running board of the car, where Norden already was coming out of his daze.

"Keep quiet!" Taylor ordered. "They'll discover us."

"They'll find us anyway!" Orkins said, frantic with fear. He groaned loudly.

"Okay. He asked for it," Masters said.

There was a splatting sound as Masters' fist landed. Masters made a face over a distasteful duty done and turned to Pember:

"Put them both in the car." He indicated Norden. "Here's handcuffs. Lock them together."

Taylor and Masters watched the circling spheres. Suddenly one darted down. From its pulsating body shot a flash of flame. A human scream rent the air.

"It's the darnedest thing I ever saw," Masters said with a shudder. "Those fireballs squirt heat-electricity out at a guy and roast him!"

"Yes," Taylor said with a nod, "and that isn't all. Those spheres act as though they were alive. When that one went out above the opening of the tunnel, I thought I saw a pair of eyes."

Masters studied the assertion, then spoke:

"Captain, I may look dumb, but I've been in the secret service long enough to be found out if I really am. I've a hunch you killed that sphere."

"I've thought of that, but how could I? I didn't touch him."

"Maybe you don't have to touch 'em to kill 'em. We don't know what they are, except they're different—"

"We don't know the real natures of anything, as far as that goes. Man's a mixture of chemicals, but that doesn't explain him. The spheres are a mixture of energies—we can observe that much, but it still doesn't explain them. Where are they from? Why did they come here? What are their primary objectives?"

"Primary objectives? That's a military term, ain't it?"

"Partly military, and partly scientific. We know the secondary objective of the spheres. It's the same as man's or any other living creature. The spheres are alive and their objective is to keep on living, but that isn't their primary motif. The primary objective is the difference between a good man and a bad one. Whatever is more important to a man than life itself is his primary objective."

"Life's pretty important," Masters said, solemnly.

"Yes, but life isn't everything. Any man, no matter how yellow or mean he is, has some ideal he's willing to die for—or at least he's willing to risk dying to attain. Look at Norden. He's hard, cold-blooded and he doesn't think twice about putting a bomb in a plant to wipe out scores of lives. He dared me to kill him, rather than help us. His code as a spy is his primary objective. Look at Pember. He must have been frightened by the spheres, but we had to force him to leave his post. We've shown him that his duty now is with us—he realizes that the spheres are the immediate enemy of his country and he'll do his best fighting them. And you and I have ideals—we know each other too well to list them."

"I getcha so far, but what about Orkins?"

"The man's not afraid of death, but afraid of the unknown. Men like him commit suicide rather than face reality. He wants security. He's afraid of uncertainty. He lives in an unreal, imaginary world and when uncertainty, which is reality, intrudes, he is completely lost."

"You make me feel sorry for the poor devil."

"That's because you understand why he's funky. Primary objectives make men do what they do—but understanding Orkins doesn't solve our problem."

"No. What are the spheres? Are they alive? If so, they must want something. What do they want?"

"A conquest of the human race?" Taylor pondered. "Maybe. But it isn't likely. They can't gain much by conquering us. It wouldn't do man any good to stage a conquest of earthworms and swordfish, since neither could pay taxes. The spheres are as different from man as man from an angle-worm. Are we a menace to the spheres? Apparently the only time we really menace them is when we crawl into a hole like a rabbit—maybe there's something in that that will help us, but I don't think that's why they kill us. Are we a nuisance? If so, why? Are we a food? There is energy in sunlight and chemicals in the human body. A creature of energy would feed on something like sunlight, not chemicals. His menu would be electric wires, storage batteries—"

"Great Scott, Captain!" Masters interrupted. "Let's get away from this car. There's a battery in it—food for the spheres!"

Masters looked nervously up at the circling globes. Taylor, deep in thought, did not stir. Instead, he continued his speculation:

"Maybe they kill us for sport."

He was thinking of small boys torturing frogs; of Roman emperors at the circus; of sportsmen exterminating game; of the mob watching the guillotine on the streets of Paris. It was Zarathustra who said that when gazing at tragedies, bull fights and crucifixions, man has felt his happiest; and when man invented hell, he made hell his heaven on earth. Couldn't this be a characteristic of all life? Couldn't the spheres be cruel and ruthless, too?

Man, the mighty hunter, had become the prey.

A sphere detached itself from the group and circled toward the car.

"I guess you're right, Masters," Taylor decided as he watched the spheres. "We'd better move."