Exactly upon the click the cruiser's driving blasts smashed on. There was a cruelly wrenching shock as everything aboard acquired suddenly a more-than-three-times-Earthly weight. The Dhilians merely twitched. The Tomigan, standing behind the pilot's seat, supporting and steadying his wounded head in its rest, settled almost imperceptibly, but her firmly gentle hands did not yield a millimeter. The nurse sank deeply into the cushioned bench upon which she was lying, her quick, bright eyes remaining fixed upon her patient. The Chickladorian girl, in her hammock, fainted quietly. And downward the big ship hurtled, tail first, directly toward the now glowing screens of a fortress. Driving jets are not orthodox weapons. But properly applied, they can become efficient ones indeed, and these were being applied with micrometric exactitude. Down--down--down! The frantic Uhalians thought that it was crashing--thought it a suicide ship. Nevertheless, they fought it. The threatened fortress and its neighbors hurled out their every beam; the Uhalian ships dived frantically at the invader and tried their best to blast her down. In vain. The cruiser's screens carried the load effortlessly. Down she drove. The fortress' screens flamed ever brighter, radiating ever higher under the terrific bombardment. Closer--hotter! Nor did the frightful blast waver appreciably; the Chickladorian was a master pilot. Down! "Set up a plus ten, Thlaskin," Cloud ordered quietly. "I missed it a bit--air density and the beams. Give it to her on the third click from ... _this_!" "Plus ten it is, sir--on!" A bare hundred yards now, and the ship of space was still plunging earthward at terrific speed. The screens were furiously incandescent, but were still holding. A hundred feet. Velocity appallingly high, the enemy's screens still up. Something would _have_ to give now. If that screen stood up, the ship must surely strike it, and vanish as she did so. But Thlaskin the Chickladorian made no move nor spoke no word to hike his blast. If the skipper was willing to bet his own life on his computations, who was he to squawk? But ... was it possible that Cloud had miscalculated? No! While the mighty vessel's driving projectors were still a few yards away the defending screens exploded into blackness. The full awful streams of energy raved directly into the structures beneath. Metal and stone glared white, then flowed--sluggishly at first, but ever faster and more mobile--then boiled coruscantly into vapor. * * * * * The cruiser slowed--stopped--seemed to hang poised. Then slowly, reluctantly, she moved upward, her dreadful exhausts continuing the devastation. "That's computin', mister," the pilot breathed. "To figure a dive like that right on the nose an' then to have the guts to hold her cold--skipper, that's computation!" "All yours, pilot," Cloud demurred. "All I did was give you the dope--you're the guy that made it good."