Inside the gateway was both sound and movement. A convulsive stirring ran along the vine-covered walls, and a sound between a hiss and a soft rustling struck their ears. Here, too, the pulsing throb was more pronounced. It was as if the plant-things of the deep jungle had over-run and conquered the city, turning it to some evil purpose of their own. The city might be dead, but the forest was alive, watching, waiting. Every wall and column was encrusted with dark masses of greenery, every avenue an alley garlanded with vines and moss. Ugly, twisting fungi and monstrous tree-ferns grew from the broken pavement. Sinister ripples of movement coursed the man and girl. The city reeked with fear. IV Security Police turned Hailard's fast cruiser back at the last barrier before the Tihar Forest--the Holy Mountains. The patrols had failed to head off the fugitive Alston before he had reached the forest, and the effort had now become a complex operation of combing the Tihar area in scout planes in the faint hope of discovering the missing 'copter and its occupants. Therefore, after putting the machinery in readiness for the job ahead, Hailard had awaited the arrival of Torkeg Nasron before taking an active part in the search. Responding to the Security Patrol signals, he leapt to the visiphone transmitter and angrily demanded explanations. A stormy interview with Nasron had done nothing for his patience. "Top priority," Hailard shouted into the transmitter, heedless of amplifiers. "All priorities are cancelled," an imperturbable junior officer told him coldly. "General Emergency. Contact Central Security in Castarona for instructions. At once. That is all." Hailard dialed the Castarona wavelength. A thin, recorded voice was broadcasting, half-newscast, half-official pronouncement. As soon as the message was finished, it was repeated for the benefit of new listeners. "--Believed that an unheard-of mutation has taken place on a large scale. No precedent. Action will be taken as soon as the full extent and nature of this fantastic development can be determined. The disturbance is of a nature both electromagnetic and atomic, and seems to be centered in the swampy districts of the extreme western range of the Tihar Forest, approximately 1,300 miles from Castarona. Little is known of this area, and the few explorations which have been attempted in the past met with disaster.