Angel relaxed his kneeholds, beating his wings furiously and climbing like a bird on a breaking treelimb. The ladder swung in giant's pendulum. Angel moved with lightning speed and miraculous precision, maintaining balance with threshing pinions while his lithe legs and powerful arms carried him upward. He was mounting the upper rungs when the ladder crashed savagely against the building side, writhing, vibrating, tearing its hooks free and sending broken masonry crashing into the dizzy depths below. Angel leaped clear, caught the parapet and dragged himself up. Guards boiled onto the jailhouse roof and laced blaster beams across the chasm between buildings. Crouched low, the fugitives ran, taking advantage of every cover. Explosions followed them and they raced through pelting storms of molten stone and metal. "Over the roofs," Ferris shouted. "They'll follow soon enough. Probably the near streets are already blocked off, and we'll need all the time we can snatch." They halted for breath in the shelter of a vast dome. Pao Chung glanced admiringly at his enforced allies. "Well-generaled," he commented. "Even to the timing of the faked fires. Too bad such talent as ours must be wasted on an audience as unappreciative as the police. However, you've kept your bargain. We're out, and still alive, with a few minutes' start, and the rooftops of the city to play hide and seek in. Now, if we can reach Khaljean's Petshop." "We'll reach it," Ferris promised grimly. II Around them was the fantastic skyline. From below, in the teeming streets, came a rising buzz like the droning activity of a hive of angry bees. Above, rose the city-wide dome of fused quartz, its crystalline concavity faintly iridescent as it reflected the questioning beams of giant searchlights. North, between the fugitives and the older native quarters of Castarona, were the gigantic systems of airlocks, and below that, the sprawling tangles of dockland. Ferris led his companions in a tortuous route that covered miles of angled and uneven rooftops. Realizing that his ident-cards must have come through, he knew that police and security officials must be turning the city inside out in a wild scramble to locate and deal with him. Speed was essential, and more than his personal safety depended upon the outcome of the wild chase over the jagged skylines. Knots of wary policemen and determined security soldiers invaded the rooftops and began searching the hundreds of square miles. In case the escaped prisoners had descended from the high levels, even business blocks were being turned out. The whole city was undergoing systematic scouring. Officialdom was desperate and badly frightened. Mechanical trackers had already been sent for. Never before had they been used so early in the game. The man, or whatever he was, Bat Ferris must be found at once, slain if possible. The hunt was on, full cry.