Arna sighed. "Let's be practical, Sy. All you know about engineering has been implanted hypnotically just for this job; all I can do is answer questions of pure math. I wouldn't know how to devise any gadgetry, and you're in no position to waste time trying--and in war some must be destroyed that others may survive." "But suppose I've just about got the thing whipped already? I've learned enough, since I've been here, to rate Mech C even home." "Sy, I just won't be a party to anything that might possibly upset League plans!" Sy's chest heaved resignedly. "Will you help me with the computational math needed to finish Operation Catskin?" "That's better!" Arna squeezed his arm happily. "Of course I will, you big, bony, restless idealist!" He smiled fondly at her--at her answer, her young beauty and her nearness. * * * * * The weeks passed swiftly--weeks in which the swarming Sur-Malic workmen ripped from their foundations the massive, cumbersome atomic converters of the mighty space fleet and replaced them with light, radically designed engines which would feed eternally upon the all-pervading cosmic emanations that streaked the universe. Sy and Arna had worked furiously. Surrounded by a corps of physicists, mathematicians, engineers, technicians and draftsmen, Arna had unerringly replied to endless queries as fast as she could speak. Sy had translated equations, converted values, integrated, correlated and directed. Subtly, he had inserted certain innocent equations of his own bit by bit, fed his results into the basic plans and disguised the all-important device with the cloak of dual function--one of which was vital to ship performance, the other of which was vulnerable to his psychokinetic ability to move objects of small mass by mental concentration alone. But all things are subject to the vagaries of pure chance. Commandant Rilth, as chief of the project, continually prowled the immense planning rooms, workshops and assembly areas, giving of his not-inconsiderable technical knowledge where needed. And one day he came upon Sy delicately checking the tiny installation which would spell doom to Alliance schemes of conquest. "You have found a flaw, perhaps?" demanded the Sur-Malic officer. He squatted and peered through the maze of ducts and cables at the shielded mechanism. Sy crawled back out of the metallic web. "Not yet," he grunted. "I was just testing my brainstorm--works like a charm." "To me," sneered Rilth, "it looks clumsy and inefficient. Could not your addled brain devise an electronic circuit, instead of a mechanical device subject to frictional wear?"