'What a nuisance these roots are,' grumbled Yattmur. "They grow everywhere!'

'The funny thing is the way the roots from one plant grow into another as well as into the ground,' Gren said, answering abstractedly. He was squatting by a branch of two roots, one of which ran back to one plant, one to another. After they had joined, they curled over a block of stone and down into an irregular gap between other stones to the earth.

'You can get down there. You will come to no harm,' said the morel. 'Scramble down between the stones and see what you can see.'

A hint of that painful tune sprang again over Gren's nerves.

He scrambled down between the blocks as he was directed, nimble as a lizard for all his reluctance. Feeling cautiously, he discovered that they rested on other blocks below, and those on other blocks below that. They lay loosely; by twisting his body he was able to slide himself down between their cool planes.

Yatmur climbed after him, showering down a gentle rain of dirt on to his shoulders.

After crawling down the depth of five blocks, Gren reached solid ground. Yattmur arrived beside him. Now they were able to move horizontally, half squashed between the walls of stone. Attracted by a lessening in the darkness, they squeezed along to a large space, large enough for them to stretch out their arms.

'The smell of cold and dark is in my nostrils and I am afraid,' Yattmur said. 'What has your morel made us come down here for? What has he to tell of this place?'

'He is excited,' Gren replied, unwilling to admit that the morel was not communicating with him.

Gradually they began to see more clearly. The ground above had fallen away to one side, for the source of light was the sun, shining in horizontally between the piled stone, sending a thin ray probing there. It revealed twisted metal among the blocks, and an aperture ahead of them. In the collapse of these stones long ago, this gap had remained. Now the only living things here beside themselves were stalker roots, twisting down into the soil like petrified serpents.

Obeying the morel, Gren scrabbled in the grit at his feet. Here was more metal and more stone and brick, most of it immovable. Fumbling and tugging, he managed to pull out some broken bits of guttering; then came a long metal strip as tall as himself. One end of it was shattered; on the rest of it was a series of separate marks arranged to form a pattern:

"That is writing,' wheezed the morel, 'a sign of man when he had power in the world, uncounted ages ago. We are on his tracks. These must once have been his buildings. Gren, climb forward into the dark aperture and see what else you can find.'

'It is dark! I cannot go in there.'

'Climb forward, I tell you.'

Shards of glass glinted dully by the aperture. Rotted wood fell away all round it as Gren put a hand forward to steady himself. Plaster showered down on his head as he climbed through. On the other side of the aperture was a drop; Gren slid down a slope of rubble into a room, cutting himself on glass as he went.

From outside, Yattmur gave a squeak of alarm. He called back softly to reassure her, pressing a hand to his heart to steady it. Anxiously he stared about in the all-but-blackness. Nothing moved. The silence of the centuries, thick and cloying, lay here, lived here, more sinister than sound, more terrible than fear.

For a spell he stood frozen, until the morel nudged him.

Half the roof had collapsed. Metal beams and brick made a maze of the room. To Gren's untutored eye, everything was indistinguishable. The ancient smell of the place choked him.

'In the corner. A square thing. Go there,' ordered the morel, using his eyesight to advantage.

Reluctantly, Gren picked his way across to the corner. Something scuttled from under his feet and out the way he had come; he saw six thick fingers, and recognized a crawlpaw like the one that had seized Yattmur's ankle. A square box three times his height loomed over him, its front surface marked by three protruding semi-circles of metal. He could reach only the lowest of these semi-circles, which, the morel instructed him, were handles. He tugged at it obediently.

It opened the width of a hand, then stuck.

'Pull, pull, pull!' twanged the morel.

Growing savage, Gren pulled till the whole box rattled, but what the morel termed the drawer would come no farther. Still he pulled, while the tall box shook. Something was dislodged from the top of it. From high above Gren's head, an oblong thing came crashing down. As he ducked, it fell to the floor behind him, sending up a cloud of dust.

'Gren! Are you all right? What are you having to do down there? Come out!'

'Yes, yes, I'm coming! Morel, we'll never open this stupid box thing.'

'What's this object that nearly hit us? Examine it and let me see. Perhaps it is a weapon. If we could only find something to help us... '

The thing that had fallen was thin, long, and tapered, like a flattened burnurn seed. It seemed to be composed of a material with a soft surface, not cold like metal. The morel pronounced it to be a container. When it found that Gren could lift it with comparative ease, it became excited.

'We must carry this container to the surface,' it said. 'You can pull it up between the stones. We will examine it in daylight and find what it contains.'

'But how can the thing help us? Will it get us to the mainland?'

'I didn't expect to find a boat down here. Have you no curiosity? This is a sign of power. Come on, move! You are as stupid as a tummy-belly.'

Smarting under this gross insult, Gren scrambled back up the debris to Yattmur. She clutched him, but would not touch the yellow case he carried. For a moment they whispered together, pressing each others' genitals to gain strength; then they struggled up between the layers of tumbled stone back to daylight, dragging and pushing the container with them.

' Phooo! Daylight tastes sweet!' Gren muttered as he levered himself up the last block. As they emerged bruised and cut into the misty air, up came the tummy-bellies scampering, their tongues lolling out in relief. Dancing round their masters, they raised a hullabaloo of complaint and reproach at their absence.

'Kill us please, pretty cruel master, before you jump again into the lips of the earth! Stab us with wicked killing before you leave us alone to fight unknown fights alone!'

'Your bellies are too fat for you to have squeezed down that crevice with us,' Gren said, ruefully examining his wounds. 'If you're so pleased to see us, why not get us some food?'

When Yattmur and he had bathed their cuts and bruises in the stream, he turned his attention to the container. Squatting over it carefully, he turned it over several times. There was a strangeness about its symmetry that alarmed him. Evidently the tummy-bellies felt the same.

'That very bad strange shape for touching is a strange bad touching shape,' one of them wailed, dancing up and down. 'Please only do a touching for throwing it into the splashing watery world.' He clung to his companions, and they peered down in silly excitement.

'They offer you sensible advice,' Yattmur said, but with the morel urging him, Gren sat down and took the container between feet and fingers. While he examined it, he felt the fungus snatch at his impressions as soon as they arrived in his brain; shivers ran along his spine.

On the top of the container was one of the patterns that the morel called writing. This one resembled

heckler or HHT303H

depending on which way you looked at it, and was followed by several lines of similar but smaller patterns.

He began to tug and push at the container. It did not open. The tummy-bellies quickly lost interest and wandered away. Gren himself would have flung the thing aside, had the morel not kept him at it, poking and pressing. As he ran his fingers along one of the longer sides, a lid flipped open. He and Yatt-mur looked askance at one another, then peered down at the object in the container, squatting in the dirt and gaping with awe.