Clipping himself to the metal strut, he locked both arms about the ladder, then dug his toes into the gap between the rung and the wall.

This time it went on and on, the whole shaft shaking like a giant organ pipe, things falling from the platform overhead. The metal track beside him groaned and for a while he thought it was going to prize itself from the wall as the metal studs strained to come away from the rock—if he wasn’t shaken from the ladder first!

How long it was he could not tell, but it seemed a small eternity before, with an echoing fall, the shaking stopped.

The sudden silence was eerie. And then something clattered onto the marble far below.

Aitrus opened his eyes. Across from him the shaft wall gaped. Cracks were everywhere now. The great molded sections were untouched, yet there were huge gaps between them now, as if the tunnel wall behind them had slipped backward. The outer wall of the spiral steps had fallen away in many places, and several of the huge securing rivets had jiggled their way out of the rock.

The sight made his stomach fall away. It had all seemed so sound, so permanent, yet one more quake and the whole shaft could easily collapse in upon itself.

Unclipping himself, Aitrus resumed his descent, ignoring the aches in his calves and shoulders, pushing himself now, knowing that time was against him. But he had not gone far when he stopped dead.

There had been a shout, just below him.

He leaned out, trying to see where it had come from, and at once caught sight of the carriage.

Some forty, maybe fifty spans below him, the track bulged away from the shaft wall, pulled outward by the weight of the carriage.

As Aitrus stared, the shout came again. A cry for help. “Hold on!” he shouted back. “Hold on, I’m coming!”

The floor of the shaft was still a good five hundred spans below, and looking at the way the track was pulled away from the wall, he knew he would have to climb along the track and over the top of the carriage if he was to help.

A length of rope would have come in handy, but he had none. All he had was a canister of air.

Making sure his grip on the ladder was good, Aitrus reached across and grabbed hold of the rail.

Just below where he had hold of it, the bolts that had pinned the track to the shaft wall had been pulled out. The question was: Would his extra weight bring a further length of track away from the wall and send the carriage tumbling down to the foot of the great shaft?

He would have to take a chance.

The outer edge of the track was grooved to match the teeth in the track that ran up one side of the carriage. The great guide wire that ran through the carriage had snapped, so that tooth-and-groove connection was all that prevented the carriage from falling. If that went …

There was the faintest rumble, deep in the earth. Things fell with a distant clatter onto the marbled floor below. The metal of the carriage groaned.

Now, he told himself. Now, before there’s another quake. Counting to five, he swung over onto the track, his fingers wrapped about the toothlike indentations in the rail, then he began to edge backward and down, his feet dangling over the abyss.

The track creaked and groaned but did not give. He moved his hands, sliding them slowly along the rail, left hand then right, his eyes all the while staring at the wall just above him, praying the bolts would hold. And then his toes brushed against the roof of the carriage.

He swallowed deeply, then found his voice again. “Are you all right?”

There was a moment’s silence, then, in what was almost a whisper, “I’m badly hurt. I’ve stopped the bleeding, but …”

Aitrus blinked. That voice.

“Veovis?”

There was a groan.

It was Veovis. He was certain of it.

“Hold on,” Aitrus said. “It won’t be long now.”

There was a hatch underneath the carriage. If he could climb beneath it and get into it that way, there was much less chance of him pulling the carriage off its guide track.

Yes, but how would he reach the hatch? And what if he could not free the lock?

No. This once he had to be direct. He would have to climb over the top of the carriage and lower himself in, praying that the track would bear the extra weight.

Slowly Aitrus lowered himself onto the roof, prepared at any moment for the whole thing to give.

He was breathing quickly now, the blood pounding in his ears. The straps from the cylinder were beginning to cut into his shoulders and for a moment he wondered if he should slip it off, together with the helmet, and let it fall, but it seemed too much effort. If he was going to die, the cylinder would make no difference. Besides, he was almost there now. He had only to slip his legs down over the edge of the roof and lower himself inside.

It was easier said than done. With his legs dangling out over the roof, he realized that he was just as likely to fall out into the shaft as he was to slip inside, into the relative safety of the carriage. Yet even as he thought it, he lost his grip and slipped. With a cry, he reached out and caught hold of the metal bar above the carriage door. His whole body was twisted violently about and then slammed against the side of the carriage.

The pain took his breath for a moment. For a full second his feet kicked out over the gap as he struggled to hold on. Then, with a grunt of effort, he swung himself inside.

The carriage creaked and groaned as it swung with him. There was the sound of bolts tearing from the wall. One by one they gave with a sharp pinging sound. With a sudden jolt the carriage dropped, throwing Aitrus from his feet, then, with another jolt, it held.

Aitrus lay on his back, the cylinder wedged under him. He felt bruised all over, but he was alive. Turning his head, he looked across the narrow floor of the carriage.

Veovis lay there, not an arm’s length from him, his eyes closed, his breathing shallow. His flesh, which had seemed pale before, was now ash white, as if there were no life in him.

Moving slowly, carefully, Aitrus got himself up into a sitting position, then edged across to where Veovis lay.

Veovis looked badly hurt. There was a large bruise at his temple, and blood had seeped through the makeshift bandage he had wrapped about his upper arm, but that would have to wait. His breathing had become erratic. Even as Aitrus leaned over him to listen to his chest, Veovis’s breath caught and stopped.

For a moment Aitrus wasn’t sure. Then, knowing that every second counted, he reached behind him and pulled the cylinder up over his head, laying it down at Veovis’s side before removing his helmet.

Precious seconds were wasted making sure the airflow was working properly; then, satisfied, he lifted Veovis’s head and slipped the helmet on, before rolling him over onto his back.

The carriage swayed then settled.

Nothing was happening …

Aitrus blinked, then felt down at the wrist for a pulse. Veovis’s heart had stopped.

Leaning over him, Aitrus pressed into his chest, leaned back, then pressed again. Veovis groaned, then sucked in air.

Aitrus sat back, knowing that he had done as much as he could. Veovis was in no condition to help himself, and on his own, Aitrus knew that he would not be able to lift the deadweight of Veovis out of the carriage and back down to the floor of the shaft.

There was a faint rumble. Again the carriage shook. Slowly the rumbling grew, stronger and stronger until Aitrus was sure that the carriage would shake itself free from the restraining track. Slowly the light faded, as if a great shadow had formed about them. Then, with a sound of rending metal, the carriage was torn from the track.

It tilted sharply forward. Aitrus caught his breath, waiting for the fall, but the carriage had stopped in midair. Slowly, the walls on either side of him began to buckle inward.

“Noooo-oh!”

The buckling stopped. With a hiss of hydraulics the carriage jerked forward, then began slowly to descend with a strange jogging motion.

Aitrus began to laugh. Relief flooded him.

It was a cutter. A cutter had climbed the shaft walls and plucked them from the track. Now, holding them between its cutting arms, it was slowly carrying them down.

Aitrus leaned across, checking that Veovis was breathing steadily, then sat back, closing his eyes, his head resting against the buckled wall.

Safe.