Her bare feet felt for and found the ladder she knew was there. Softly she felt her way down the rungs. Silently she groped for the latch in the door at the bottom. She cracked it open and a line of light blinded her briefly. The familiar sour-sweet smell of yeast drifted into her nostrils.

This Ark must be built after the same plan as Ark Three. There would be a stack of elevators at the centre, connecting the five floors below ground and the Dome garden above. But slaves were forbidden to use the elevators, except on special Lords' business. The rest of the time they were supposed to be invisible. If only she were! Nothing would suit her purpose better at this moment. She must find the stairs. How lucky that the training on Ark Three had involved stair-climbing. She knew just where they should be. If the plans were identical.

She eased the door open. The closest vat was fifteen metres or so away. Someone stood beside it reading numbers off an instrument panel and transferring them to a clipboard. His bald head shone in the glare of the overhead lights. He wore brown coveralls. He must be a worker then. They were supposed to be quite stupid. What she must beware of was the blue of the Lords and the red of the soldiers.

The room was orderly, bright and white. 'Keep to the shadow paths,' Stargazer had advised her. She looked to her right. About a hundred and fifty metres around the perimeter should be a door leading to the stairs. How could she get there unseen? The shadow paths? Not only must she avoid the bright pools of light that splashed onto the floor but, and this was more important, stay out of sight of the television monitors that must be scanning the huge laboratory. These, she had been told, were connected, via the Computer, to the infopaks of the soldiers, the Three-eyes, who were themselves walking monitors, since they bore small video cameras on their foreheads.

She squinted up at the bright ceiling. There they were: a cluster of four cameras, each pointing in a different direction. An all- seeing computer connected to an all-seeing army. How could she and the others hope to outwit such odds? She closed the door and leaned against it, thankful for the sheltering darkness.

I can't go through with it. I just can't.

You can't let the others down either. Come on, Ruth. You've always wanted to be a useful part of the Web. Now's your chance.

Suppose they capture mc? Maybe torture mc with those horrible machines plugged into my neck like that poor worker over there?

Don't be stupid. The worst that could happen would be if they made you a slave. Then you could escape, just like Swift and Healhand. Come on, Ruth. Better to be a slave than go back across the dam to the others and say you can't do it.