Nikkia was frantically polling all of the city's defense commanders. They reported failure with monotonous regularity. The electronic barrage wall around the city had been passed easily--the equipment wrecked. A proton bombardment had yielded exactly nothing--He snapped the switch, peered eagerly at the mist curtain overhead--there was a series of heavy concussions. The glowing visitors were being bombarded from above. The screen glowed again.... "... but the bombs are all detonated long before they get in effective range of...." Close by a vague shape--a darker shadow in the muggy air, suddenly materialized. It was falling swiftly--a familiar cylindrical shape with rounded ends--one of the Jovian guard ships. It struck scarcely a hundred yards from the palace--struck with a jarring burst of sound like rending metal. Then utter silence again, and darkness. No cry of wounded man. No man could survive that fall and live. "Some kind of emanation--shields them from all known attack--" Nikkia swore monotonously and regularly. The glowing ships now settled down to the real purpose of their attack. They began to course back and forth across the city, methodically. Like burning meteors they disappeared over the horizon, to the city's farthest suburbs, back again, as if over a measured and marked course. And like burning, melting meteorites, they shed trails of sparks, blazing liquid. Wherever these fiery drops landed there ensued immediately a dry crackling, followed by the rattle of falling masonry. As none of the buildings were inflammable, there was no danger of fire. But wherever this incendiary trail fell, stone cracked and crumbled. "They are destroying us! Forty million people live here in Rubio. They will kill us all, women and children too!" "_Who_ are _they_?" Sine asked suddenly. * * * * * Nikkia looked at him bleakly. "Who? Why, the Mugs, of course! Those we banished. Those we thought we wiped out." "Oh, yeh." Sine's intonation was very dry. "They're giving you a dose of your own medicine." Nikkia did not reply. As if he apprehended, too late, that his statement might have sounded like a plea for help, he shrugged his massive shoulders with elaborate indifference, saying; "I and my wives are not afraid to die!" The Earthmen could no longer watch this ruthless destruction, however, regardless of the provocation. "You say that pink light is a protection against every _known_ mode of attack?" Sine asked, turning sharply to the governor. "Yes. And that's sufficient, isn't it?" "Is it proof against _this_?" Sine jerked the little tube out of its clip, directed it against a stone parapet that loomed grotesquely through the fog. A brilliant white beam leaped forth, cutting the fog like a bar of platinum. Then there was darkness, and the governor, examining the parapet, noted with growing hope that a stone pillar, a foot in diameter, had been cut off smoothly, cleanly.