Strata

down.’
    ‘I’m flying blind,’ complained Silver. ‘You must direct me so that I don’t hit the ground.’
    ‘You won’t,’ said Marco.
    Kin let herself drop, tensing herself for the crash until she came out of the smoke into moonlight.
    Shining upwards
.
    Vertigo gripped like a wrench. She could take space, because everywhere was down and direction lost its meaning. Skimming over a landscape was fine, it was no different than driving an aircar.
    But not this. Not hanging legs down over a hole in the world.
    The moon was directly below, hovering nearinfinity at the bottom of a tunnel that went down and down and down …
    ‘Five miles deep, wouldn’t you agree, Silver?’ said Marco in the distance. ‘And at least two wide. Are you all right, Kin?’
    ‘Hunh?’
    ‘You’re still descending.’
    She fumbled dizzily for the suit controls. On a level with her eyes, a quarter mile away, was the lip of the hole, striated with bands of rock. Lower – she forced her eyes to move slowly. More bands, then a line of something metallic.
    And a pipe, gushing water. Kin started to laugh hysterically.
    ‘We’re fine!’ she giggled. ‘We don’t need to go any further, all we have to do is wait for the repairmen! You know what it’s like with plumbers, when you want one they’re never—’
    ‘Cease gibbering. Silver, see to her,’ snapped Marco. Kin saw his hand poised over his chest panel. Then he dropped, fast. Her eyes started to follow him down before Silver’s gloved paw jerked her round. She felt motion, and realized dimly that she was being steered away from the hole.
    After a while she heard Marco say, ‘There’s a pipe thirty metres across. Guess what? The water’s pooling about two miles down – on air. That’s why we’re not in the middle of a descending hurricane, there’s some kind of a gravity basedown there. There’s going to be one hell of a lake there soon.
    ‘I’ve gone down forty metres. It looks like an explosion in a power station. There’s sheared – cables, I guess, multicored, and what could be waveguide tubes or access tunnels or something. Silver?’
    ‘I hear you. I suggest the ship impacted on top of one of the disc environmental machines, which blew up,’ said the shand.
    ‘It looks like it. There’s a lot of fused stuff and – scrub that. Here’s a tunnel, a real tunnel. Can you hear me? I’m hovering in front of a semicircular tunnel, it’s even got rails in it! The whole of the interior of the disc is one big machine! You should see this hole, it’s big enough for a spaceship. There’s, uh, eighteen rails across the floor. Access for machinery repairs. I assume, but it’s half choked with rubble.’
    ‘The ship impacted five days ago,’ said Silver sombrely. ‘They have had five days in which to effect repairs. The disc builders are dead, Marco. There can be no other explanation.’
    ‘I can see no signs of repair,’ came the voice from the pit.
    ‘Quite so. Something has gone wrong somewhere, just as the seas are erratic and the heavenly bodies misbehave. Which way does the tunnel run? Is there a continuation on the further side of the pit?’
    There was a pause.
    ‘Yes, I can see the other mouth of the tunnel. It runs direct from the rim to hub,’ said Marco. ‘I had considered suggesting we continue our flight along the tunnel but—’
    ‘—it would be better to face any dangers in the open sky. Precisely.’
    Kin opened her eyes. She was hovering over blessed earth – scorched, maybe, baked and half molten, but solid.
    ‘Thanks,’ she said. ‘Stupid, wasn’t it? My forebears used to hang from trees by their knees.’
    ‘No shame,’ said Silver. ‘I do not like darkness. We all have our phobias. Kin? You look a little pale …’
    Kin didn’t try to speak. She knew she couldn’t. She managed a strangled grunt, and pointed.
    Something was rising out of the pit, with difficulty. That difficulty arose because it was almost too big. All she could think of was the Mt Tryggvason Memorial.
    It was one of the Valhallian tourist attractions. Someone had carved the high-relief heads of Presidents Halfdan, Thorbjorn, Weasel Moccasin and Teuhtlile out of solid rock a few hundred feet high in the side of the mountain.
    That was what was rising out of the pit – a Mt Tryggvason with one head missing, a three-headed Thing. Only the head facing them was human. The others could have been a monstrous toad and some sort of insect, giant faces