So it is with the spacemen who drift from Pluto to Mercury Darkside, trusting to metal hulls that shut in the air and shut out the vast abysses of interplanetary space. When they work outship, a glance at the sky will tell a trained man where he is--and only tough, trained men survive the dangerous commerce of space. On Mercury the blazing solar corona flames above the horizon; on clouded Venus the green star of Earth shines sometimes. On Io, Callisto, Ganymede, a man can orient himself by the gigantic mother planet--Saturn or Jupiter--and in the Asteroid Belt, there is always the strange procession of little worlds like lanterns, some half-shadowed, others brightly reflecting the Sun's glare. Anywhere in the System the sky is friendly-- Except on Asgard. Jupiter was too far and too small; Mars was scarcely visible; the Asteroid Belt not much thicker than the Milky Way. The unfamiliar magnitudes of the planets told Stuart, very surely, that he was on unknown territory. He was without the sure, safe anchor that spacemen depend upon, and that lack told him how utterly he stood alone now. But the unreasoning confidence did not flag. If anything, it mounted stronger within him as he hurried along the road, his rangy legs eating up the miles with easy speed. The sooner he reached his goal, the better he'd like it. Nor did he wish to encounter any more of the Aesir's guardians--his business was with the Aesir! The tower of light grew taller as he went on. Now he saw that it was a cluster of buildings, massed cylinders of varying heights, each one gigantic in diameter as well as height, and all shining with that cold, shadowless radiance that apparently came from the stone--or metal--itself. The road led directly to the base of the tallest tower. It ran between shining pillars--a gateless threshold--and was lost in silvery mists. No bars were needed to keep visitors out of this fortress! Briefly a cool wind of doubt blew upon Stuart. He hesitated, wishing he had at least his blaster gun. But he was unarmed; he had even left the club back in the forest. He glanced around. The red moon was sinking. A heavier darkness was creeping over the land. Very far away he thought he saw the shifting flicker of dancing lights--a Watcher? He hurried onward. Cyclopean, the tower loomed above him, like a shining rod poised to strike. His gaze could not pierce the mists beyond the portal. He stepped forward--between the twin pillars. He walked on blindly into the silver mists. Twenty steps he took--and paused, as something dark and shapeless swam into view before him. A pit--at his feet. In the dimness he could not see its bottom, but a narrow bridge crossed the gulf, a little to his left. Stuart crossed the bridge. Solidity was again under his feet. With shocking suddenness, a great, brazen bellow of laughter roared out. Harsh mockery sharpened it. And it was echoed.