"And that offense is to be—?"

"I have no idea. We will work that out together."

Again they went into a union of minds; considering, weighing, analyzing, rejecting, and—a few times—accepting. And finally, well within the five-day time limit, they had drawn up a completely detailed plan of battle.

How uselessly that time was spent! For that battle, instead of progressing according to their carefully worked-out plan, was ended almost in the instant of its beginning.


According to plan, Tregonsee tuned his mind to "X's" pattern as soon as they had come within working range. He reached out as delicately as he could; and his best was very fine work indeed. He might just as well have struck with all his power, for at the first touch of the fringe, extremely light and entirely innocuous though it was, the stranger's barriers flared into being and there came back instantly a mental bolt of such vicious intensity that it would have gone through Tregonsee's hardest-held block as though no barrier had been there. But that bolt did not strike Tregonsee's shield; he did not even know, until much later, that it had been sent. Instead, it struck Karen Kinnison's, which has already been described.

It did not exactly bounce, nor did it cling, nor did it linger, even for a microsecond, to do battle as expected. It simply vanished; as though that minute interval of time had been sufficient for the enemy to have recovered from the shock of encountering a completely unexpected resistance, to have analyzed the texture of the shield, to have deduced from that analysis the full capabilities of its owner and operator, to have decided that he did not care to have any dealings with the entity so deduced, and finally, as he no doubt supposed, to have begun to retreat in good order.

His retreat, however, was not in good order. He did not escape, this time. This time, as she had declared that she would be, Camilla was ready for anything—literally anything. Everything she had—and she had plenty—was on the trips; tense, taut, and poised. Knowing that Karen, the Ultimate of Defense, was on guard, she was wholly free to hurl her every force in the instant of perceiving the enemy's poignant thrust. Scarcely had the leading element of her attack touched the stranger's screens, however, when those screens, "X" himself, his vessel and any others that might have been accompanying it, and everything tangible in nearby space, all disappeared at once in the inconceivably violent, the ultimately cataclysmic detonation of a superatomic bomb.

It may not, perhaps, be generally known that the "completely liberating" or "superatomic" bomb liberates one hundred percent of the total component energy of two or more subcritical masses of an unstable isotope, in a space of time estimated to be sixty-nine hundredths of one microsecond. Its violence and destructiveness thus differ, both in degree and in kind, from those of the earlier type, which liberated only the energy of nuclear fission, very much as the radiation of S-Doradus differs from that of Earth's moon. Its mass attains, and holds for an appreciable length of time, a temperature to be measured only in millions of Centigrade degrees; which fact accounts in large part for its utterly incredible vehemence.

Nothing inert in its entire sphere of primary action can even begin to move out of the way before being reduced to its subatomic constituents and thus contributing in some measure to the cataclysm. Nothing is or becomes visible until the secondary stage begins; until the frightful globe has expanded to a diameter of some hundreds of miles and by this expansion has cooled down to a point at which some of its radiation lies in the visible violet. And as for lethal radiation—there are radiations and they are lethal.