Ouch! She saw stars as her head crashed into something very solid above her. In the faint light from the passage below she saw a round metal cover set in a narrowed collar at the top of the shaft. There was a handle in the centre that had to be pushed around. She slipped one leg through a rung for safety, reached up and pushed.

The handle moved more easily than had the bolts of the door. It swung through a ninety degree are and the heavy lid fell towards her. She ducked and clung to the ladder as the edge of the heavy lid grazed her shoulder. It swung from its hinges and the noise of its fall echoed up and down the passage.

It died away at last into a silence of dust and ghostly memories and Ruth dared to look up. Above her was more blackness. Another lid!

She forced herself to stand on the topmost rung and reach through the neck to the ladder that logic told her must be there on the other side. Her hands grasped it. She swung through and reached up eagerly to the handle of the second lid.

This one, she worked out, must open outwards. The handle swung easily through its ninety degree are. She pushed. And pushed again. She climbed a rung higher, so that her shoulder was against it. I won't give up now. Not when I'm so close. She took a deep breath and heaved until her shoulder muscles cracked.

There was a creaking sound. A line of bright light appeared. She pushed again and a blaze of warm sun fell on her face. The lid clanged back and she climbed up blindly into the sunshine and rolled over the edge of the shaft to drop into a bed of sweet- smelling grass.

She was free at last! Free of the Ark and the demands of the Web. She lay on her back in the grass with her eyes still shut, savouring the silence. After a few moments she became aware of a sighing rustle, almost as rhythmic as the air conditioners in the Ark. The wind, she told herself, as it touched her check. I am listening to the wind in the grass.

She began to hear other sounds, small creaks and clicks that she couldn't identify. Then, just as had happened in her dream, a sudden buzz made her jump, open her eyes and sit up.

Directly in front of her was the concrete shaft, sticking out of the grass, that was the entrance to Ark Three. Around and beyond it was grass, green and gold, sun-dried, sweet smelling, scattered with flowers. There were grasses with spiked seeds, grasses with plumy purple tops, grasses whose hard heads were speckled with yellow pollen.