Thinking thus, the man of gray sat coldly motionless at his great multi-shielded desk, whose top was now swung up to become a board of massed and tiered instruments and controls. He shut off his offensive beams and surrounded the entire planetoid with the peculiarly rigid and substantial shield which had so easily warded off Costigan's fiercest attacks. And that shield was more effective than even its designer had supposed--gray Roger had builded even better than he knew. For the voracious and all-powerful converting beam of the Nevians, below the level of the ether though it was, struck that perfectly transparent wall and rebounded, defeated and futile. Struck and rebounded, then struck and clung hungrily, licking out over that impermeable surface in darting tongues of red flame as the surprised Nerado doubled and then quadrupled his power. Fiercer and fiercer drove in the Nevian flood of force until the whole immense globe of the planetoid was one scintillant ball of scarlet energy, but still the pirates' shield remained intact--at what awful drain of resource, Roger alone knew. "Here is the analysis of his screen, sir." A Nevian computer handed his chief a sheet of metal, upon which were engraved rows of symbols. "Ah, a sixth-phase polycyclic. A screen of that type was scarcely to have been expected from such a low form of life," Nerado commented, and rapidly adjusted the many dials and switches before him. As he did so the character of the clinging mantle of force changed. From red it flamed quickly through the spectrum, became unbearably violet, then disappeared; and as it disappeared the shielding wall began to give way. It did not cave in abruptly, but softened locally, sagging into a peculiar grouping of valleys and ridges--contesting stubbornly every inch of position lost. And gray Roger knew that the planetoid was doomed. His supposedly impregnable screen was failing in spite of its utmost measure of energy, and, that defense down, the citadel would not last a minute. Therefore he summoned a chosen few of his motley crew of renegade scientists and issued brief instructions. For minutes a host of robots toiled mightily, then a portion of the shield bulged out, extended into a tube beyond the attacking layers of force, and from it there erupted a beam of violence incredible. A beam behind which was every volt and ampere that the gigantic generators and accumulators of the planetoid could yield. A beam that tore screamingly through the ether; that by the very vehemence of its incalculable energy tore a hole through the redly impenetrable Nevian field and hurled itself upon the inner screen of the fish-shaped cruiser in frenzied incandescence. And was there, or was there not, a lesser eruption upon the other side--an almost imperceptible flash, as though something had shot from the doomed planetoid out into space?