Naomi launched the first missile straight for their airlock. It struck just before the emergency siege gate slid shut, blasting jagged holes through the outer and inner locks. Air whooshed from the dome, hurling men and debris into the vacuum. Seconds later the catastrophe seal was oozing down to plug the hole, but by then our ship had plunged through. "You've done it!" Naomi screamed joyously. "We're inside!" "And their fleet is outside, and there's nothing the boys can do about it." I slowed our ship to practically zero ground speed. We hovered for a moment near the ceiling of the great transparent dome, considering our next target. Below us lay the ramshackle gangland, a maze of roofless partitions clustered around a tiny lake. One quarter of the city was virtually an open-air machine shop. Near the shattered airlock stood a parade ground, overlooked by a tall, balconied tower with people on top making frantic gestures. "I'll bet that's headquarters." "Down it goes," said Naomi excitedly. I put our ship in a dive. She aimed quickly, triggered the missile. _Boom!_ The tower collapsed. Tiny figures began to scurry about on the parade ground. "Let's get 'em!" I skimmed the field and Naomi blazed away with the vibro gun. One after another the boys dissolved in puffs of smoke. I veered around and we strafed them again, killing hundreds. I felt exhilarated, marvelously happy. Naomi shrieked ecstatically. In another minute there were no more boys alive who hadn't taken shelter underground. I glanced upward and laughed. The boys' fleet swarmed helplessly outside the dome like bugs on a lampshade, watching their hangout ripped to pieces. "Get their arsenal!" cried Naomi. "Revenge for Phyllis!" We dived again, spraying the roofless barracks with destruction, blasting huge craters in their machine shop, starting explosions of ammunition that rocked our ship, threatening to blow off the dome in one piece. At last the fun ended. "Only one missile left," Naomi warned. "Hang on, then," I said gaily, stabbing the rocket controls. "Callisto girls are homeward bound!" _Blam!_ went our torpedo, tearing a second hole in the mangled airlock. And out that hole we went, accelerating like crazy, pursued into deep space by the entire enemy fleet. * * * * * As long as we were chased, and missile fragments rattled against our hull, we continued in high spirits. Even when the boys scored a hit that forced us to don our space suits, we remained elated. But the minute the Ios broke-off pursuit we renewed our antagonism. "Say," said Naomi over her helmet phone, "this isn't the right course for Callisto." "No, dear, I'm landing on Ganymede first. I don't think it's safe to go on until we get that fuel leak fixed." "Why should we pay good money to a mechanic when our own girls can do the job?"