Eyes continued to grope all around--at newness to them which was eons old. In the near distance was what seemed a highway. It ran east and west. One end vanished among the gloomy hills, at the fringe of the frigid hemisphere of eternal night. The other end reached straight across the plain toward where the top edge of the sun blazed supernally. In that direction the Twilight Belt turned gradually into unequalled desert. Sunward along that highway, several ruined domes were visible, like scattered castles. They looked ancient Martian. Beyond them, out of sight, there must be others--buildings never made to offer shelter from the continuous, blazing radiation to which they were now exposed. Also in sight on the highway was the wreck of a great turtle-like war engine, its triangular prow marking it as a probable product of Planet X. Doubtless, too, it had been an automatic, unmanned thing, capable of seeking out enemies by radar, and attacking, on its own, even without remote control. But if there was fear among those who saw it that the energy in it would be reawakened by their presence, this was dispelled as far as it was concerned. It lay on its side, torn out of shape, knocked out on the road those ages ago. "Jeez!" some young guy muttered. Then Nostrand spoke again, expressing most everyone's mood: "Mercury was different when it rotated on its axis. Torrid, yes. But solar heat was nowhere continuous. Nor was darkness and cold. There were nights to cool off the heat of day. But the tidal drag of the too-near sun slowed the rotation. It must have stopped rather suddenly, as a wheel spinning against considerable friction stops. Then everything on Mercury changed, became extreme. It must have happened just about when the Martians and Xians were fighting each other. Maybe both sides held part of the planet at first...." Nostrand's tone was musing and remote, hinting at pictures of ancient history. In his mind Rick Mills saw those dim pictures. His hide tingled. And his eyes combed the surrounding hills and plain warily. Was he looking for strange movement? This thought was tied up with the knowledge that, as on the moon, automatic machines could be perfectly preserved for millions of years here on weatherless Mercury, and that in some of them power might still be triggered into action by the disturbance of something penetrating a radio aura around them. Rick spent some minutes with this scrutiny. By mood, nothing but a little dust and scant air molecules ever should stir on this tomblike planet. Once he may have imagined something small crawling on a hillside. But the second time, in a boulder-strewn gulch toward the dark hemisphere, and only a quarter-mile away, he could not be mistaken. A shape, hunched under a heavily loaded rucksack, was hurrying and dodging away. A man in space armor!