They were all downstairs now, waiting to be fed, hardy perennials like all children everywhere. Thomas with his shining morning face—it seemed to stay that way right up until bedtime—and Susan, seven, and still doll-wedded, and the twins, Hedy and Louise. Three girls and one boy, and Grace Lynton felt a little sorry for her son at times, until she remembered that a boy of thirteen isn't troubled by too many girls in a family when he's seven or eight years their senior. The girls were simply very young children to him and he was—well, right next door at least to being grown up.

"All right," John Lynton said, seating himself at the head of the table. "Let's fall to and see who gets through first."

"Did you have a tough day, Dad?" Thomas asked, reaching for a knife and fork, and drawing a still steaming serving bowl toward him. His unruly hair was so blond it seemed almost white and there was a double row of freckles across the bridge of his nose.

The other three children were brunettes, with hair ranging in color from chestnut brown to jet black. Even the twins did not closely resemble each other, as non-identical twins so often fail to do.

"Don't annoy your father with questions now, Thomas ... please," Grace Lynton said.

"Why not?" Lynton asked, frowning at his wife. "I did have a tough day and there's no sense in soft-pedaling it. Sometimes I almost wish we hadn't come to Mars. No matter how rigorous a Board screening is ... there are some things it can't tell you about yourself. Will you make a good father on a world without trees or grass, with no way of getting out into the green countryside and sitting down on the moss-covered bank of a trout stream, with your kid at your side and having a heart to heart talk with him in the cool shade of a big oak or cedar."

"The stew's good, Mom," Thomas said. "Is it all right if I fill up my plate again?"

"Did I ever say you couldn't, Thomas?" Grace Lynton snapped, unable to keep irritation out of her voice, despite her son's compliment. "There'll never be any food shortages in this house, if we have to sell all of the furniture."

"Leave enough for me, Thomas," Hedy Lynton said.

"Don't worry, I will," Thomas said. "But if you keep on eating the way you do you'll grow up fat, and no man in the Colony will marry a fat woman when there are so many thin ones."

"That's very well put, Thomas," Lynton said. "I have a brilliant son—practically a genius. But don't let it go to your head, boy. Unless you're in the electronic field or have some other technical specialty a straightforward, rugged he-man can do more for the Colony."

"What kind of talk is that, John?" Grace Lynton demanded. "There's nothing unmanly about a genius, in any field."

"No, I suppose not. But I wouldn't want him to be a poet or a painter. They just stand back and observe life and I'd like to see my son wade in fighting."

The daylight outside had started fading before Lynton and his wife had returned indoors. But now the quickly-arriving Mars' night was almost at hand, and the twilight had deepened outside and was giving way to complete darkness at the edge of the desert.

The two adults and four children seated about the table hadn't once glanced toward the window, for the food and contentious conversation had absorbed all of their attention.

It was Thomas who saw the light first, flickering on and off close to the shed. He had always wanted, deep down, in a secret way that he had never dared to discuss with anyone, to be an artist and paint at least a hundred pictures that would show the people who looked at them exactly what life on Mars was like. And his father's gaze, trained upon him in such a steady way, had made him squirm inwardly, as if his secret might at any moment be exposed. To avoid his father's gaze he'd looked straight out the window and seen the strange light flickering on and off.

"Dad!" he said.

"What is it, son?"

"There's a light moving around out in the yard, close to the shed."

If Thomas had suddenly toppled over dead his father could not have leapt up from the table with more horror in his eyes.

"Why ... why ... Good God! Wendel wouldn't go that far! It would be an act of madness!"

"John, you don't think—"

Thomas' mother was on her feet too now, her face drained of all color, her eyes darting to the window and back to the tight-lipped, violently trembling man at the head of the table. John Lynton's face had gone as white as her own.

For a minute Thomas thought that his father was going to rush right out into the yard and grab hold of the intruder, as fast as he'd leapt up from the table. Then he saw he'd guessed wrong about that.

Lynton crossed the room in five long strides, swung open the weapon locker and grabbed hold of a holstered hand-gun instead. He strapped the holster to his waist before whipping out the weapon and snapping off the safety mechanism.

He was starting for the door when Grace Lynton called out warningly: "John, don't! John!"

He swung about, staring at her in consternation. "Don't what? If they've tampered with those cylinders I'll make sure they won't live to blow up another man's home—or half the Colony!"

"You can't blast them down!" Her voice rose shrilly. "No, John! A hand-gun blast that close to a fuel cylinder would set off a chain reaction—"

"No, it won't. The blast is channeled. Don't be a fool, Grace. I know what I'm doing."

"You're the fool! You'll get us all killed!"

"If they've tampered with just one of those cylinders we won't have to worry about what a hand-gun blast will do. But they won't save their own skins before the big blast hits us. That's one thing I can make sure of."

He turned and was gone. She started to follow him out into the yard, but became aware of how dangerous that would be just in time. If she followed her husband the children would almost certainly follow her, for she couldn't order them to stay indoors and hope to be obeyed.

She rushed to the window and stared out, her face pressed to the pane.

She could feel Thomas pressing close to her—or was it Hedy or Susan? There was a heaviness in his body which made her almost sure it was Thomas. But that meant nothing, because she loved all of her children equally.

Suddenly she was sure it was Thomas, because he was speaking to her. "Take it easy, Mom! Dad'll take care of whoever it is. He's got a hand-gun to protect him."

"Oh, I know he has!" she wanted to scream. "It will be a beautiful way of protecting us all ... by sending us straight into eternity. God, dear God, don't let him blast. Don't—"

The blast came then, lighting up the darkness outside, making the windowpanes rattle. For an instant Grace Lynton could see her husband clearly, standing by the shed with a white flare spreading outward from his shoulders.

Then the flare dwindled and vanished and Grace Lynton had no way of knowing what had happened outside in the dark. She was sure of only one thing. She couldn't stay inside the house with her husband moving about a few feet from fuel cylinders that might blow up at any moment, for there was at least a fifty percent likelihood that the intruder had accomplished what he'd come to do, before Thomas had seen the light bobbing about in the yard.

She had straightened and was hugging her son to her, just starting to turn, when John Lynton's voice rang out sharply from the doorway.

"Grace! I blasted at him but he got away! Listen carefully. I've only a moment to talk."

He was standing in the doorway with the hand-gun reholstered at his waist, its handle gleaming dully. His pallor was startling, for it went far beyond mere paleness, as if all the blood had been drawn from his face artificially, leaving the skin gray and shrunken.

"I can't be sure, but I think ... one of the cylinders has been triggered to blow up," he went on quickly. "It isn't heating up. There'd be no heat—just a faint vibration. When I put my hand on the metal I was almost sure I could feel a vibration. We've got just one chance of staying alive—and I'll have to move fast. I'm going to take it to the Spaceport—I can get there in the conveyor truck in ten minutes—and have them dismantle it. They'll know how. I don't. I'll take all six of the cylinders, to make sure."

"John, no! It will blow up in the truck. I'm sure of it. We'd better all get out in the desert, as far away from it as we can. If we start right now and run—"

"We could go in the truck, Dad!" Thomas cried.

Lynton shook his head. "If just one cylinder blows up—it will take three miles of desert with it. If all six go ... twenty miles of desert. There are at least six thousand Colonists within three or four miles of us. There are less than a thousand people at the Spaceport. Only one big sky ship is still unloading. Better a thousand deaths than six or seven thousand ... if it blows up before they can dismantle it."

"But John—Oh, God, I don't know."

"It's the best way, the surest way. We can't think only of ourselves. If I drove straight out into the desert with it and it blows up within twenty minutes the fallout would still kill several thousand Colonists. The Spaceport's in the other direction, completely isolated. And I can get there in fifteen minutes ... even if I'm stopped by the Wendel police and have to blast my way to it."

"Why should they try to stop you? They'd die themselves—"

"Why did they send someone to trigger that bomb? They'll take any risk now, because they know that Endicott's new bluff could smash them. That cylinder is smaller than the first atomic bomb ever built—much smaller than the one that was dropped on Hiroshima—and if they have to explode a half-dozen of them in different parts of the Colony to demoralize the Colonists and discredit Endicott they're prepared to do it, apparently. Even if it kills thirty thousand people. Or maybe they figured the one I'm taking to the Spaceport—and I am taking it there, Grace—would make the Colonists think twice about taking any more Endicott fuel cylinders home with them."

"You're right, John," Grace Lynton said, with a firmness in her voice which surprised her. "We can't think only of ourselves. Until you come back—every moment will be a living death. But—you must do it. There's no other way."

"I'll be back," Lynton said. "I—I love you, Grace."

"And I love you, John—even though I've said cruel, cutting things at times. I love you very much."

"Take care of yourself, Dad," Thomas said.

"I will, son. Don't worry. Just be the man of the family and keep the kids in line until I get back."

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