But he was right in the first place. It _was_ a mystery--something to do with the startling news that she was on the way, that closer friendship was pending. The impulse to go meet her had been his first, almost thoughtless impulse. He was still glad that she wasn't out between Mars and the Belt, where disaster had once hit him hard. But now he wondered if the Survey Station was any better for anybody, even though it was reputed to be quite secure. The caravan he rode approached his destination no closer than ten million miles. Taking cautious note of radar data which indicated that space all around was safely empty, he cast off in his Archer with a small, new, professional-type bubb packed across his hips. Inside his helmet he lighted a cigarette--quite an unusual luxury. It took a long time to reach Phobos. They gave him shots there--new preventative medicine that was partially effective against the viruses of Mars. Descent in the winged rocket was rough. But then he was gliding with a sibilant whistle through a natural atmosphere, again. Within minutes he was at the Station--low, dusty domes, many of them deserted, now, at the edge of the airfield, a lazily-spinning wind gauge, tractors, auto-jeeps, several helicopters. He stepped down with his gear. Mars was all around him: A few ground-clinging growths nearby--harmless, locally evolved vegetation. Distant, coppery cliffs reflecting the setting sun. Ancient excavations notched them. Dun desert to the east, with little plumes of dust blowing. Through his Archer--a necessary garment here not only because the atmosphere was only one-tenth as dense as Earth-air and poor in oxygen, but because of the microscopic dangers it bore--Nelsen could hear the faint sough of the wind. The thirty-eight percent of terrestrial gravity actually seemed strong to him now, and made him awkward, as he turned and looked west. Perhaps two miles off, past a barbed-wire fence and what must be an old tractor trail of the hopeful days of colonization, he saw the blue-green edge of Syrtis Major, the greatest of the thickets, with here and there a jutting spur of it projecting toward him along a gully. Nelsen's hide tingled. But his first glimpse was handicapped by distance. He saw only an expanse of low shagginess that might have been scrub growths of any kind. Dug into the salt-bearing ground at intervals, he knew, were the fire weapons ready to throw oxygen and synthetic napalm--jellied gasoline. Never yet had they been discharged, along this defense line. But you could never be sure just what might be necessary here. A man of about thirty had approached. "I meet the new arrivals," he said. "If you'll come along with me, Mr. Nelsen..." He was dark, and medium large, and he had a genial way. He looked like a hopper--an asteroid-miner--the tough, level-headed kind that adjusts to space and keeps his balance.