beginning for my benefit, Commissioner," Art interposed. "What!" roared Horne. "Theller gave me to understand that you had had experience with these things, and understood them. Now you tell me—" "Easy, Commissioner. I've seen one of these things before for a few minutes, and that's all. You asked for help and Dr. Theller sent me out here in good faith to do what I can." This served to quiet the policeman somewhat, for he merely grunted, "O.K., meet me at the top level of the Administration group; that's the silver one, the only one that still has a top level. You'll have to find it. We had to move out the traffic control—that section of the building's ready to go any minute now." A dull grinding roar rose from everywhere below Art as he crossed the city. Clouds of dust billowed up as the huge pyramids fell in upon themselves piece by piece. He saw now the grimly effective way in which the creatures did their job. As long as there was one piece left standing on another, they would bore and chew until it was reduced to fragments. Blind instinct, rather than malice, seemed to impel them. But the effect was equally devastating. Art saw scores of people wiped out by falling wreckage when the rapidly shuttling overloaded fliers failed to remove them in time. He saw one man, trapped amidst a mass of the writhing horrors, make a sudden dash for freedom, and go down screaming in agony as dozens of savage jaws instantly fastened themselves in his flesh. Art shuddered. Something had to be done to stop this carnage. By the time he sighted the commissioner's flier atop the silver pyramid of the Civic Center, he had evolved the rudiments of a plan. He wasted no time on amenities as he met the police chief, but came to the point immediately. "Here's my idea of it, Horne. Los Angeles as a city is doomed. But I think we can save most of the people who are still here." "How about those disintegrators?" cut in Horne. The disintegrator, being still in the experimental stage, was dynamite in the hands of the untrained. The terrific atomic explosions it set up were uncontrollable and unpredictable. Only the most highly respected and trusted scientists were even allowed to handle one. Horne nursed an idea that all his patrolmen should have been issued one to pack on their hips, and that if they had, this would never have happened. "I have a couple with me. We can use them, but we'll have to be extremely careful. My main proposal is to get