They fell softly into that circle. Its mountainous sides were high; they blocked off the view of the enormous terraces beyond that had been the crater's sloping sides. From the direction that had suddenly become "east," the rising sun's strong light struck in a slant to make the bar rocks seem incandescent. On one side the giant rim of the encircling mountains was black with shadow. The shadow reached out across the vast, rocky floor almost to the foot of the opposite wall many miles away. It enveloped their falling ship like a cushioning, ethereal sea: velvety, softly black, almost palpable. It was wrapping them about in the darkness of night as Chet's slender hand touched so delicately upon the ball-control--checked them, eased off, drew back again until the thundering exhausts echoed softly where their ship hung suspended a hundred feet above a rocky floor. The shrouding darkness erased the harsh contours of mountain and plain; it seemed shielding this place of desolation and horror from critical, perhaps unfriendly eyes of these beings from another world. And Chet laid their ship down gently and silently on the earthlit plain as if he, too, felt this sense of intrusion--as if there might be those who would resent the trespass of unwanted guests. But Spud O'Malley must have experienced no such delicacy of feeling. He let go one long pent-up breath. "And may the saints protect us!" he said. "The Lake of Death outside, and inside here is purgatory itself, or I don't know my geography. But you made it, Chet, me bhoy; you made it! What a sweet little pilot you are!" * * * * * "There's air here," Chet was telling his companion later; "air of a sort, but it's no good to us." He pointed to the spectro-analyzer with its groupings of lines and light bands. "Carbon dioxide," he explained, "and some nitrogen, but mighty little of either. See the pressure gage; it's way down. "But that won't bother us too much. We've got some suits stowed away in the supplies that will hold an atmosphere of pressure, and their oxygen tanks will do the rest. We were ready for anything we might find on our Dark Moon trip, but we didn't need them there. Now they'll come in handy." "That's all right," O'Malley assured him; "I've gone down under water in a diving suit; I've gone outside a ship for emergency repairs in a suit like yours when the air was as thin as this; I can stand it either way. But what I want to know is this: "What the divil chance is there of findin' your man, Haldgren, in such a frozen corner of purgatory as this? How could he live here? Here you've come in a fine, big ship, and his was a little bit of a bullet by comparison. Yet I doubt if you could live here for five years with all your big oxygen supply. Now, how could he have done it with his little outfit?