Against the glow of the green light inside the cavern he saw a nightmarish monster rising to its feet. Both pistols stabbed viciously as the monster thrust forward a thick, bristly leg to shut the door again.

A ray bit off the leg at the second joint. The other ray ripped open the soft, tumid abdomen. Penrun had barely time to throw himself aside as the convulsed, dying monster hurled itself tigerishly forward through the doorway out into the driving storm in a final frenzied effort to seize and rend his frail human enemy.

Penrun slipped into the cavern. The deathly cold outside would finish the horrible insect. As he kicked the big door shut he was crouched and tense, for the ancient gray attendant monster whose poisoned bite had paralyzed thousands for this living hell was moving forward curiously.

Both pistols flamed to life. The fearsome head of the monster with its poisoned mandible shriveled to nothing under the searing rays. Penrun sprang backward and jerked open the door. Then he closed it again. The old spider was moving feebly. Instead of the galvanic death of the guard, the huge gray insect's legs buckled under it and it slumped down to the floor of the cave where it quivered a few seconds, then relaxed in death.

As Penrun stepped forward around the carcass the cave filled with hysterical screams and hoarse insane shouting of joy and terror. He looked up at the high vaulted roof where the strange diamond-shaped crystal diffused its green light along the shimmering silken web, then turned his gaze downward to the rock floor beneath his feet. At last he gritted his teeth and forced himself to look at the walls.

Again he saw tier upon tier of hammocks, each holding a naked human being, helpless and paralyzed from the poisoned bite of the attendant monster spider. Some could weep, some could smile, some could talk, yet none could move either hand or foot. A few were mercifully unconscious, but the rest were not. Many were insane. Yet they all lay alike year after year, century after century, if need be, kept alive by the rays of the strange green light in the roof. This was the cavern of the Living Dead!

Penrun knew the tragic future of these unfortunates. A few, perhaps, would go as food for the Queen in times of famine. The remainder would become living incubators for the larvae of the Queen which would be planted in their living bodies by the monster attendant to eat away the vitals until death mercifully ended the victim's life, and the growing spider emerged to feed on a new victim, or to go its way.

A thousand helpless human beings swung in their silken hammocks awaiting their fate. Penrun had learned about them during those two horrible days he had been held prisoner here before he had succeeded in raying the novice attendant and the monster guard with the pistol from his armpit holster that the spiders had overlooked when they captured him. He recalled again how he had dashed frantically from hammock to hammock trying to rouse some of the Living Dead to escape with him. Not one of them could respond.

Reports to the Interplanetary Council? He had made them, written and oral, and had only been laughed at for a half-crazy explorer. The Council would not even investigate.

Now Penrun did not tarry. He strode swiftly back to the far end of the cavern.

"The girl who was just brought in, is she safe?" he asked hoarsely.

None seemed to know, but presently he knew she was still unhurt, for he found her bound hand and foot to the rock wall with heavy silken webs. Nearly all her clothing had been torn off her. She looked up hopelessly. A great fear appeared in her eyes.

"You!" she gasped. "Are you responsible for this?"

"I have come for you," he replied in a matter-of-fact tone, swiftly removing the pack from his back.

She cowered against the wall.

"You—you inhuman beast!" Her face was white with horror.

He cut the silken bonds.

"Don't be a fool!" he said roughly. "I have no power over these monsters. Hurry into those clothes! Do you want to be bitten in the small of the back and lie paralyzed for years in a hammock like these other unfortunates, then suffer untold agony for months while spiders' larvae eat out your vitals? Hurry, I say! We must get out of here at once!"

He turned away. He wanted to see that old Englishman who said he had known Shakespeare. His wish was in vain. The old man's sightless eyes stared up at the silken roof. The long, heavy beard that lay across the breast stirred. The beady, glittering eyes of an infant spider peeped out. Penrun uttered a curse of loathing. His pistol stabbed death into the foul insect.

He felt a touch on his arm. The girl was waiting.

"I am ready," she said quietly. "Oh, let us hurry!"

Dawn was lighting the world outside, and the driving blizzard was already changing to rain. Penrun seized the girl's hand and ran madly up the mountainside toward the peak. The spiders usually did not venture out in the rain, but in the face of danger from the ship they would be abroad as early as possible this morning.

Penrun suddenly spurted madly. Half a dozen gigantic spiders were moving cautiously along the lower edge of the city, their bodies looming up grotesquely in the misty rain. The girl stumbled, struck her head against a boulder, and lay still. Penrun caught her up in his arms and sprinted madly up the steep slope.

A rock loosened by his flying feet rattled and pounded down the hillside. Instantly the monsters whirled round, sighted him and started in pursuit. With a mighty leap he cleared a ten-foot ledge, carrying his unconscious burden, and plunged into the sheltering mist of the clouds. Up, up! Thank God for the weak gravity!

A swishing rattle of claws on rock shot by them in the fog, turned and swept back. Penrun sprang straight upward, rising nearly a dozen feet in the air as the monsters streaked past underneath.

Only a little farther! Savagely he forced his failing strength to carry them up the slope. The air was chilling fast and the mist thinning. He broke into clear air as the fog behind them filled with the rattle of racing claws on the barren granite and the grating roar of the baffled monsters, seeking frantically for their intended victims.

He staggered on another hundred yards before he collapsed with lungs laboring desperately in the rarefied air.

Below them a bristly monster charged out of the fog, sighted them lying up among the rocks, and leaped after them. Penrun jerked up a pistol with trembling fingers and loosed its deadly ray. The huge spider stumbled and ploughed head-on among the rocks with a flurry of legs. It rose loggily, for its fierce energy was dwindling rapidly in the biting cold. Again the pistol crackled. The gigantic insect toppled over and rolled down the mountainside into the fog and vanished.

"Are we safe now?"

Penrun turned. The girl was now sitting up somewhat unsteadily, with an ugly bruise on her forehead.

"I think so," he replied. "Up there in my space-sphere we shall be quite safe."

Together they plodded silently up the sharp incline of the peak, her hand in his. And as they went he marveled that her eyes could be so beautiful now that the fear and horror had vanished from their depths.

The storm clouds below had broken up and dissolved under the increasing heat, revealing the Trap-Door City, seemingly deserted, and the motionless black ship still resting on the plateau. Penrun turned to the girl beside him in the control nest of the space-sphere.

"What are your friends waiting for all this time?" he asked abruptly.

"They're not my friends," she retorted. "And you might have guessed that they are waiting for you to arrive with the other third of the map. They are planning to surprise you and rob you of it.