touched he drove with his wonted cool skill; even though, consciously, he did not know that the other cars were there. He slowed, turned, stopped, "gave her the oof," all in correct response to flashing signals in all shapes and colors—purely automatically. Consciously, he did not know where he was going, nor care. If he thought at all, his numbed brain was simply trying to run away from its own bitter imaging—which, if he had thought at all, he would have known to be a hopeless task. But he did not think; he simply acted, dumbly, miserably. His eyes saw, optically; his body reacted, mechanically; his thinking brain was completely in abeyance.

Into a one-way skyway he rocketed, along it over the suburbs and into the transcontinental super-highway. Edging inward, lane after lane, he reached the "unlimited" way—unlimited, that is, except for being limited to cars of not less than seven hundred horsepower, in perfect mechanical condition, driven by registered, tested drivers at speeds not less than one hundred and twenty-five miles an hour—flashed his registry number at the control station, and shoved his right foot down to the floor.

Now everyone knows that an ordinary DeKhotinsky Sporter will do a hundred and forty honestly-measured miles in one honestly measured hour; but very few ordinary drivers have ever found out how fast one of those brutal big souped-up Sixteens can wheel. They simply haven't got what it takes to open one up.

"Storm" Cloud found out that day. He held that two-and-a-half-ton Juggernaut on the road, wide open, for two solid hours. But it didn't help. Drive as he would, he could not outrun that which rode with him. Beside him and within him and behind him. For Jo was there. Jo and the kids, but mostly Jo. It was Jo's car as much as it was his. "Babe, the big blue ox," was Jo's pet name for it; because, like Paul Bunyan's fabulous beast, it was pretty nearly six feet between the eyes. Everything they had ever had was that way. She was in the seat beside him. Every dear, every sweet, every luscious, lovely memory of her was there ... and behind him, just out of eye-corner visibility, were the three kids. And a whole lifetime of this loomed ahead—a vista of emptiness more vacuous far than the emptiest reaches of intergalactic space. Damnation! He couldn't stand much more of—

High over the roadway, far ahead, a brilliant octagon flared red. That meant "STOP!" in any language. Cloud eased up his accelerator, eased down his mighty brakes. He pulled up at the control station and a trimly-uniformed officer made a gesture.

"Sorry, sir," the policeman said, "but you'll have to detour here. There's a loose atomic vortex beside the road up ahead—

"Oh! It's Dr. Cloud!" Recognition flashed into the guard's eyes. "I didn't recognize you at first. You can go ahead, of course. It'll be two or three miles before you'll have to put on your armor; you'll know when better than anyone can tell you. They didn't tell us they were going to send for you. It's just a little new one, and the dope we got was that they were going to shove it off into the canyon with pressure."

"They didn't send for me." Cloud tried to smile. "I'm just driving around—haven't my armor along, even. So I guess I might as well go back."

He turned the Special around. A loose vortex—new. There might be a hundred of them, scattered over a radius of two hundred miles. Sisters of the one that had murdered his family—the hellish spawn of that accursed Number Eleven vortex that that damnably incompetent bungling ass had tried to blow up.... Into his mind there leaped a picture, wire-sharp, of Number Eleven as he had last seen it, and simultaneously an idea hit him like a blow from a fist.

He thought. Really thought, now; cogently, intensely, clearly. If he could do it ... could actually blow out the atomic flame of an atomic vortex ... not exactly revenge, but.... By Klono's brazen bowels, it would work—it'd have to work—he'd make it work! And grimly, quietly, but alive in every fiber now, he drove back toward the city practically as fast as he had come away.

If the Lensman was surprised at Cloud's sudden reappearance in the laboratory he did not show it. Nor did he offer any comment as his erstwhile first assistant went to various lockers and cupboards, assembling meters, coils, tubes, armor, and other paraphernalia and apparatus.

"Guess that's all I'll need, Chief," Cloud remarked, finally. "Here's a blank check. If some of this stuff shouldn't happen to be in usable condition when I get done with it, fill it out to suit, will you?"

"No," and the Lensman tore up the check just as he had torn up the resignation. "If you want the stuff for legitimate purposes, you're on Patrol business and it is the Patrol's risk. If, on the other hand, you think that you're going to try to snuff a vortex, the stuff stays here. That's final, Storm."

"You're right—and wrong, Phil," Cloud stated, not at all sheepishly. "I'm going to blow out Number One vortex with duodec, yes—but I'm really going to blow it out, not merely make a stab at it as an excuse for suicide, as you think."

"How?" The big Lensman's query was skepticism incarnate. "It can't be done, except by an almost impossibly fortuitous accident. You yourself have been the most bitterly opposed of us all to these suicidal attempts."

"I know it—I didn't have the solution myself until a few hours ago—it hit me all at once. Funny I never thought of it before; it's been right in sight all the time."

"That's the way with most problems," the Chief admitted. "Plain enough after you see the key equation. Well, I'm perfectly willing to be convinced, but I warn you that I'll take a lot of convincing—and someone else will do the work, not you."

"When I get done you'll see why I'll pretty nearly have to do it myself. But to convince you, exactly what is the knot?"

"Variability," snapped the older man. "To be effective, the charge of explosive at the moment of impact must match, within very close limits, the activity of the vortex itself. Too small a charge scatters it around, in vortices which, while much smaller than the original, are still large enough to be self-sustaining. Too large a charge simply rekindles the original vortex—still larger—in its original crater. And the activity that must be matched varies so tremendously, in magnitude, maxima, and minima, and the cycle is so erratic—ranging from seconds to hours without discoverable rhyme or reason—that all attempts to do so at any predetermined instant have failed completely. Why, even Kinnison and Cardynge and the Conference of Scientists couldn't solve it, any more than they could work out a tractor beam that could be used as a tow-line on one."

"Not exactly," Cloud demurred. "They found that it could be forecast, for a few seconds at least—length of time directly proportional to the length of the cycle in question—by an extension of the calculus of warped surfaces."

"Humph!" the Lensman snorted. "So what? What good is a ten-second forecast when it takes a calculating machine an hour to solve the equations.... Oh!" He broke off, staring.

"Oh," he repeated, slowly, "I forgot that you're a lightning calculator—a mathematical prodigy from the day you were born—who never has to use a calculating machine even to compute an orbit.... But there are other things."

"I'll say there are; plenty of them. I'd thought of the calculator angle before, of course, but there was a worse thing than variability to contend with...."

"What?" the Lensman demanded.

"Fear," Cloud replied, crisply. "At the thought of a hand-to-hand battle with a vortex my brain froze solid. Fear—the sheer, stark, natural human fear of death, that robs a man of the fine edge of control and brings on the very death that he is trying so hard to avoid. That's what had me stopped."

"Right ... you may be right," the Lensman pondered, his fingers drumming quietly