The captain sprang to his feet. "You get it, Penrun. You'll have to hurry. I want no more murders aboard my ship. Here, down this private stairs to the sphere air-lock. I'll make arrangements by phone. Once you are free of the liner I'll slow down so that the black ship will have to slow down, too. That will give you a chance to pull away and get a good start on them."
Five minutes later Penrun's newly acquired craft was sliding out of its air-lock in the belly of the monstrous liner. He pulled away and glanced back.
The liner was already slowing down. The black pursuing craft was hidden by its vast, curving bulk. Penrun crowded on speed as swiftly as he dared. By the time the strange craft had made contact with the Western Star his little sphere had dwindled to a mere point of light in the black depths of space and vanished.
Penrun leaned over his charts grimly, as he set a new course for the sphere to follow. He, too, could play at this game. He'd carry the battle to the enemy's gate. Out to Titan he'd go and match his familiarity with the little planet against the superior numbers of his enemies.
Ten days later, Earth time, he was circling Titan, while he searched the grim, forbidden terrain beneath. After days of studying and speculation he had decided that the Caves must be situated in the Inferno Range, a place so particularly vicious that no man, so far as was known, had ever explored it. During the day the heat would boil eggs, and at night the sub-zero cold cracked great scales off the granite boulders. And here, too, lay the Trap-Door City of the monster spiders!
The grim, fantastic range soon appeared over the horizon, stabbing its saw-tooth peaks far into the sky. Dawn was still lighting the world, and a great snow-storm, a howling, furious blizzard, concealed the lower slopes of the mountains. Penrun knew that presently the driving snow-flakes would change to rain-drops, and the shrieking, moaning voice of the gale would give way to the crashing, rolling thunder of the tempest. As the day advanced the storm would die abruptly and the clouds vanish under the deadly heat.
Then the Trap-Door City, which covered the slopes above the plateau at the three-thousand-foot level like a checker-board of shimmering, silken circles, would spring to febrile life as the spider monsters went streaking and leaping across the barren, distorted granite on the day's business, the hunt for food in the lowlands, and the opening of the trap-doors to gather in the heat of the day in the silken tunnel homes set in the gorges and among the boulders. At sunset the doors would all be closed, for then the rain and the electrical storm would return, and at night the blizzard. The storm-and-heat cycle was the deadly weather routine of the Infernos.
Penrun steered for a tall, cloven peak that towered high above the Trap-Door City. In its thin air and continuous cold he would be comparatively safe from marauding spider scouts, and from the peak he could watch not only the city of the monsters but the better part of the Inferno Range as well.
He was convinced that before long the mysterious black craft would put in an appearance somewhere near this spot. Penrun knew it all too well. There by the cataract of the White River, half a mile across the plateau from the insect city, he had once been captured.