The long low barracks at the Spacers' Training school outside Washington buzzed and growled with the hundreds of blue-uniformed spacers. There at the far end of the hall on the little platform where the sergeants took the roll, Wing stood looking at the hard-bitten, space-burned men who had been land-bound since they turned from victory to answer that fatal six-two.... They had come because their commander had offered them a fight; a little different perhaps using old-fashioned projectile weapons, but nevertheless a fight; and they, who had used space guns against the shadow-things, who had been beaten back without a chance to fight, were spoiling for battle. Some of them were reading the hastily-printed instructions that came with the bright, shining, but outmoded weapons. Some were a little jealous of other comrades who even now were hurling their atomic bolts through the skies over Earth as they harassed the vanguard of Zhan Nekel's Mercurian fleet. But with the pangs of jealousy they had pride in themselves, too. While their shipmates battled a known enemy, they were going out to fight against an unknown enemy with untried weapons and only the promise of their Space Commander, Curt Wing, that these weapons, three centuries old, could win where atomics had so miserably failed. Wing raised his hand for attention. "Some of you knew Dead-Eye and his Elizabeth. He's gone now, but he destroyed three of the shadow-things with leaden pellets from his old sixshooter before he died. He showed me the way to lick those shadows. Simply, it's this. A concentration of powder can open a hole in the atomic shield of the shadows. But in our atomic weapons we have a flow of power and it's sucked away by the shield before it can concentrate. "In Elizabeth, Dead-Eye had concentrated power--the leaden projectile. Its comparatively inert atoms struck the shield and broke through before it could be spread out evenly over the shield. "For a moment, the shield was out of balance. That's your job and mine--keep that shield out of balance until we can find the invaders within and destroy them. "I realize that you've had only five days to study what these old weapons are and how they operate--but we haven't any more time. We've got to lick an enemy from outside and an enemy from within at one and the same time. "Do you think we can do it?" A roar of assent greeted him. They numbered in the thousands. Space rovers of the Twenty-fourth century, moving in a long, spread out line toward the edge of the blue flower that still pulsated and grew, reaching farther and farther out from White City. Curt Wing's heart was filled with pride--pride in these thousands who, with strange, obsolete arms, were moving against a shadowy foe equipped with weapons the like of which they'd never dreamed; pride in that unbeatable spirit and courage of man, the magnificent fool, who had lifted himself by his own bootstraps from the caves of Earth to the vast reaches of the stars!