Down! DOWN!! The threatened fortress and its neighbors hurled their every beam; Nhalian ships dived frantically at the invader and did their useless best to blast her down. Down she drove, the fortress’ screens flaming ever brighter under the terrific blast. Closer! Hotter! Still closer! Hotter still! Nor did the furious flame waver—the Chickladorian was indeed a master pilot. “Set up a plus ten, Thlaskin,” Cloud directed. “Air density and temperature are changing. Their beams, too, you know.” “Check. Plus ten, sir—set up.” “Give it to her on the fourth click from . . . this.” “On, sir.” The vessel seemed to pause momentarily, to stumble; but the added weight was almost imperceptible. A bare hundred yards now, and the ship of space was still plunging downward 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 _had_ to give now! If that screen stood up the ship would vanish as she struck it, but Thlaskin the Chickladorian made no move and spoke no word. If the skipper was willing to bet his own life on his computations, who was he to squawk? But . . . he must have miscalculated! No! While the vessel’s driving projectors were still a few yards away the defending screens exploded into blackness; the 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 for an instant poised. Then she darted upward, her dreadful exhausts continuing and completing the utter devastation. “That’s computin’, mister,” the pilot breathed as he cut the fierce acceleration to a heavenly one thousand. “To figure a dive like that to three decimals and have the guts to hold to it cold—skipper, that’s com-pu-_tation_!” “All yours, pilot,” Cloud demurred. “All I did was give you the dope. You’re the guy that made it good. Hurt, anybody?” Nobody was. “QX. We’ll repeat, then, on the other side of the lagoon.” As the ship began to descend on the new course the vengeful Dhilian fleet arrived. Looping, diving, beaming, oftentimes crashing in suicidal collision, the two factions went maniacally to war. There were no attacks, however, against the plunging Tellurian ship. The Nhalians had learned that they could do nothing about that vessel. The second fortress fell exactly as the first had fallen. The pilot landed the cruiser in the middle of the shallow lakelet. Cloud saw that the Dhilians, overwhelmingly superior in numbers now, had cleared the air of Nhalian craft. “Can you fellows and your ships keep them off of my flitter while I take my readings?” “We can,” the natives radiated happily.