 How many caves had Garmon and Rolf traveled through before their crash?
Sisko Rolf's stocky body was a blur of motion as he cut the rocket jets, doused the twin searchlights, and switched over to the audio beams that served so well on the surface when blind flying was in order. But here in the cavern world, thirty-seventh in the linked series of vast caves that underlie the waterless wastes of Mars, the reflected waves of sound were of little value. "Trapped us neatly," Rolf said through clenched teeth. Rolf swung the lax controls over hard as the bursts of fire revealed a looming barrier of stone dead ahead, and then he felt the tough skin of the flyer crumple inward. Somehow Rolf found the strength to wrap his fingers around the control levers and snap on a quick burst from the landing rockets. The ship struck; split open like a rotten squash, and Rolf felt himself being flung far outward through thick blackness. There could be no ascent from this natural prison-pit, and even if there were he could never hope to reach the surface forty miles and more overhead. The floors of the thirty-seven caves through which they had so carefully jetted were a splintered, creviced series of canyon-like wastes, and as he ascended the rarefied atmosphere of the higher levels would spell death. Without water and food certain death grinned in his face, for beyond the sand-buried entrance to these lost equatorial caves there were no pressure domes for hundreds of miles. Half of the oval bar he crushed between his teeth, and when the concentrated energy flooded into his muscles he set off around the irregular wall of the pit. How many hours later it was when the first faint glow of white light reached his eyes Rolf did not know—it had seemed an eternity of endless plodding along that smooth-floored descending tunnel. "They may have found the sunken seas of Mars," thought Rolf as he moved alertly forward, "water that would give the mining domes new life." As the spinner dropped him slowly down into the vast emptiness of the great shining gulf, Rolf could see that a broad band of stone divided the green fertile plains and forests from the desolate desert wastes of the other half. Toward this barrier the spinner bore him, and Rolf was content to let it move in that direction—from the heights of the wall he could scout out the country beyond. The spinner had slowed its speed; it seemed to Rolf that he must be falling free in space for a time, but the feeble gravity of the tiny world tugged at him more strongly as he neared the wall.
 thirty seven
 thirty seven  forty seven  thirty  forty