A thousand feet below, the local equivalent of a forest grew, the trees, topped with huge ragged leaves, looking like hundred-foot stalks of celery. There would be animal life down there, too--little round things, four inches across, like eight-legged crabs, gnawing at the vegetation, and bigger things, two feet long, with articulated shell-armor and sixteen legs, which fed on the smaller herbivores. Beyond, in the middleground, was open grassland, if one could so call a mat of wormlike colorless or pastel-tinted sprouts, and a river meandered through it. On the skyline, fifty miles away, was a range of low dunes and hills, none more than a thousand feet high. No human had ever set foot on the surface, or breathed the air, of Niflheim. To have done so would have been instant death; the air was a mixture of free fluorine and fluoride gasses, the soil was metallic fluorides, damp with acid rains, and the river was pure hydrofluoric acid. Even the ordinary spacesuit would have been no protection; the glass and rubber and plastic would have disintegrated in a matter of minutes. People came to Niflheim, and worked the mines and uranium refineries and chemical plants, but they did so inside power-driven and contragravity-lifted armor, and they lived on artificial satellites two thousand miles off-planet. This vehicle, for instance, was built and protected as no spaceship ever had to be, completely insulated and entered only through a triple airlock--an outer lock, which would be evacuated outward after it was closed, a middle lock kept evacuated at all times, and an inner lock, evacuated into the interior of the vehicle before the middle lock could be opened. Niflheim was worse than airless, much worse. The chief engineer sat at his controls, making the minor lateral adjustments in the vehicle's position which were not possible to the automatic controls. One of the radiomen was receiving from the orbital base; the other was saying, over and over, in an exasperatedly patient voice: "Dr. Murillo. Dr. Murillo. Please come in, Dr. Murillo." At his own panel of instruments, a small man with grizzled black hair around a bald crown, and a grizzled beard, chewed nervously at the stump of a dead cigar and listened intently to what was--or for what wasn't--coming in to his headset receiver. A couple of assistants checked dials and refreshed their memories from notebooks and peered anxiously into the big screen. A large, plump-faced, young man in soiled khaki shirt and shorts, with extremely hairy legs, was doodling on his notepad and eating candy out of a bag. And a black-haired girl in a suit of coveralls three sizes too big for her, and, apparently, not much of anything else, lounged with one knee hooked over her chair-arm, staring into the screen at the distant horizon. "Dr. Murillo. Dr. Mur--" The radioman broke off in mid-syllable and listened for a moment. "I hear you, doctor, go ahead." Then, a moment later "What's your position, now, doctor?"