They were out of breath again from running when they reached the heavily forested region. The dark barrier of vegetation which loomed before them cut off two-thirds of the sky and seemed filled with a vast murmuring, as if a thousand small furry creatures were breathing in unison while the wind sighed between the trees and owls hooted from the higher branches.
Quickly they passed into the dark wilderness between the trees, over areas of moist peat moss and across gigantic, hollow logs overgrown with ghost-pale creepers that seemed dreamlike and unreal in the half-light. A faint luminescence streamed from a few of the ground-hugging fungus growths and there were vapor shrouds everywhere, hanging suspended in the air and coiling sinuously about the boles of trees so massive that they resembled redwoods in girth and height, and conveyed an even more awesome impression of hoary age.
They were perhaps eighty feet beyond the edge of the forest wall, well within its pulsing heart of darkness, when they heard the thrumming.
It was faint and far-off at first, but it grew steadily louder, causing Teleman to halt abruptly and stare upward in alarm. High above his head the interlocking branches formed an almost solid ceiling of dark green foliage stirred only slightly by gusts and flurries of wind. Suddenly, as he stared, a gust of unusual force blew two of the branches apart, revealing a narrow patch of open sky.
Across the patch a shape moved, glinting metallically in the sunlight.
The flying machine hung poised almost directly overhead, like a great, hovering hawk with its wings wide-spread. It was moving, but slowly, slowly, as if seeking out prey in the forest aisle, the thrumming of its twin turbines sounding very much like the steady beating of wings.
The foliage overhead stirred again and the patch of open sky disappeared.
"They know where we are," Teleman said, standing very still. Alicia shivered and moved a little closer to him, her lips white. Above their heads the thrumming sound grew in volume, drowning out all the small voices of the forest. Almost at their feet a startled hare broke from cover and went scurrying into the shadows.
"If they're scanning us now it will be easy for them to send a para-guard after us," Alicia said, her eyes sharpening as she stared upward. "He'll be carrying a hand-scanner, and a hand-gun. He'll have no scruples about opening fire."
"They may drop more than one para-guard," Teleman said. "We'd better head for cover fast!"