He linked his hand through hers and they stood on the slope above the path, their wills binding the mass of wet clay that trembled on the bulge of the mountain above them.

“Gil, Basil, Helen.” The Initiator's voice called out the names as the others hurried up the path. “Thomas, Crystal, Val, Olga.”

Nineteen, she thought. Only nineteen.

“Angela, hurry!” The Initiator's voice was like a knife. “Run for your life. Come on! They can't hold on much longer. “

The sulky expression on Angela's face turned to one of terror and she began to run, slipping and sliding on the twisting path. Ruth felt her arms and legs shake. Sweat streamed down her face. Then Luke tightened his grip on her hand and whirled her round. They too were scrambling on hands and knees along the

steep slope above the path, away from the river.

A single gust of wind, like an enormous sigh, blew up their hair. They turned in time to see the trees lean forward at an insane, impossible angle. Slowly, gracefully, they began to slide down the slope. Quietly at first. Then, with a grinding deafening roar trees, rocks and mud poured down the mountainside into the river.

The roar echoed up and down the valley. It was followed by a silence so profound that Ruth thought for an instant that she had gone deaf. Then she realised that the voice of the river, which had been with them constantly for the last two days, had been silenced. The path they had followed had been wiped out and a slump of boulders, splintered trees and mud filled the valley and held back the mountain torrent. Behind this natural dam the river rose slowly, brown and foamy. Before long there would be a lake where they stood. Later, perhaps, a waterfall. Where the bulge of hill had overhung the path was a reddish-brown gouge like a fresh bleeding wound. Angela's sobs broke the silence.

“It's all right. Everyone's safe.” Charity consoled her.

“It's not. Don't you understand? We're trapped. We'll never get back to Ark Three. Never.”

“Nonsense,” the Initiator said briskly. “Luke will find another way home. What concerns me more is that no one except Ruth seemed to guess what was going to happen. Why ?”

“I was picking up a lot of negative noise,” said Thomas, after a pause. “From the group,” he added, and everyone's eyes went to Angela and then quickly flickered away.

“All right. We'll talk about that tonight. Luke, how far do we still have to go?”

Luke unfolded his map and spread it on a rock. “Another two hours' climbing should bring us to a good place.”

“Can you all make it? Very well, let's go. No straggling please. Obviously the heavy rain caused that instability. It could happen again.”