'Shh!' She punched him on the shoulder.

A lyrinx appeared between the boulders as if it had materialised from the air. Another one followed, carrying something between it and a third. They slipped across the open s.p.a.ce into the trees.

'Minis?' Tirior said.

Minis had his ear to a funnel-shaped implement. 'They're heading away to the south-west. There were only those three.'

'Can you hear them with that?' Nish asked.

'I can feel their footsteps.'

They waited. Tirior was watching the movement of lines upon the gla.s.s.

'What is it?' said Nish.

'They have sentinels of a sort I'm not sure how to deal with.'

'Sentinels?'

'Patterned devices that sense the aura of the Art and set off an alarm. They never sleep; never fail. Nothing of the Art can get past them.'

Nish asked no more questions.

'Minis?' said Tirior, 'would you go below and bring up the packet on the bench?'

He did so. She handed it to Nish. 'A chance to prove yourself. See that smaller rock, the seventh in from the left-hand side, low down?'

'Er ... The round one that's narrower underneath?'

'Yes. It's a sentinel. Go up onto the hill and approach it from above, quietly. Unwrap the package before you get there. It contains a net lined with gold foil. Be careful you don't tear it. Slip the net over the sentinel from above and pull it all the way to the ground, leaving no gaps. Then crush this with your fingers and push it under.' She pressed something like a small egg into his hand. 'When I signal, bring back the net and the foil. We may need to use it again.'

'Why me?'

'You bear no trace of the Art.'

'What if there are lyrinx sentries?'

'They'll eat you and I'll have to find another way, which will vex me. Get moving.'

The unpleasant part was, he felt sure she was telling the truth. Nish crept across the dry gra.s.s, which crackled alarmingly. His pa.s.sage was even noisier as he moved up the hill, for the ground was littered with crunchy bark and dry sticks. The piled boulders above would make a perfect place for an ambush.

As he reached the lowest boulder a whiff of something came to him something strongly, muskily animal. Lyrinx Lyrinx. He froze against the rock, head c.o.c.ked to one side. A breeze stirred the treetops; just a whisper. There was no other sound. The creature, or creatures, could be anywhere. They could probably smell him. And he was unarmed.

But Minis had said they were all gone. He must just be smelling the scent left behind, or from the hole they'd come out of. He waited another minute but heard and smelt nothing more.

Tirior would be getting impatient. Nish had one foot in the air when something thumped onto one of the higher boulders further around the hill. It was definitely a lyrinx he heard the squeal of its claws against the rock.

Another joined it, followed by three more thumps. Nish did not dare to breathe. Even the most cursory search must find him. There was a mutter in the lyrinx tongue and the unmistakable flap of leather wings unfolding. Thup-thup, thup-thup Thup-thup, thup-thup. A lyrinx pa.s.sed across the sky, and another beside it. They were carrying something between them, suspended in a net. It looked like a long box.

They disappeared into the dark. After a moment's silence the others moved out, one by one. All wore bulky packs. They looked around, then headed down the hill, going west.

Nish counted to five hundred, and even then felt anxious. He had no way to tell if more were coming but the risk had to be taken. He went up among the boulders, unfolded the net carefully and crept toward the sentinel. It looked very rock-like. He studied it closely. It was was a rock he a rock he was was looking at the wrong one. looking at the wrong one.

He found the sentinel. Holding out the net, he tiptoed towards it, whipped the net over and pressed it down. The sentinel did not move, of course. It was not alive, strictly speaking.

Taking the other object from his pocket, he crushed it in his fingers. A nauseating stench wisped out, like the rottenest of rotten eggs, and something slimy clung to his fingers. Nish thrust the mess under the net and held it down. He wiped his fingers repeatedly but could not get rid of the smell.

What now? Tirior was supposed to signal. He climbed onto a rock, looking in the direction of the hidden construct. Nothing. He got down again. The sentinel seemed to be collapsing. Nish was watching it, wondering what to do, when he was seized by the arm. He struggled desperately to get free.

'It's me, Minis,' Minis hissed. 'Why are you waiting here? Come on.'

'I thought you said they were all gone,' Nish grumbled as they went back to the construct.

'I thought they were. Hurry up.'

The construct moved forward until it was between the boulders. Tirior handed Nish what appeared to be a wire helmet. 'Put this on.'

'What is it?'

'Something to stop your little brain melting.'

'I ' He could never tell if she was serious. He put it on.

'Come on,' said Minis.

Nish climbed out after him. 'What are we supposed to be doing?'

'Don't talk! Grab the other side and lift.'

Nish took hold of what looked like solid rock and heaved. It was not rock either and tilted back to reveal a dark cavity.

'Hold it open.'

The little construct, slightly more visible than before, edged forward. Minis thrust his funnel inside the entrance and signalled to Tirior. She stood up, held something elongated to her shoulder and pointed it down the hole. An amber glow spiralled around its length and shot underground. Minis checked again with the funnel. He waved. The construct tilted over the edge and slid down. They followed.

A breeze drifted past, carrying the scent of crushed leaves. The false rock came down over Nish's head, shutting out the light. All was black for an instant, then a light-gla.s.s came on at the front of the construct. They clambered inside and the construct moved down the narrow tunnel at walking pace. Shortly they encountered the bodies of two lyrinx by a sentry post.

'If you can kill them so easily,' said Nish, 'why don't you use these weapons in the war?'

'It was not easy,' said a blanched Tirior. 'I will suffer for days, and no one else can use it at all.'

'How did you find this tunnel?' Nish asked.

'Not by flapping my mouth at every opportunity. Minis, go to the firing position.'

Minis jacked up the rear turret, where a pair of devices used compressed springs to fire various kinds of projectiles. He armed both weapons.

'Nish, put your ear to the funnel. Call if you hear anything.'

Nish heard an amplified whine, a ticker-tick-tick ticker-tick-tick, but no thumping footsteps. The tunnel wound around as if following weaknesses in the rock, then ran flat and straight for a few minutes before diving steeply and coiling around several times. At this lower level, water was seeping through the roof, making puddles on the floor.

They slid around a corner of yellow rock. Ahead was a second guard post with two lyrinx by it. They had not heard or seen the construct. In the funnel Nish heard pfft pfft. The lyrinx in the middle of the tunnel fell, transfixed through the heart. The other hurled himself for the guard post but a spear went through his back, dropping him short. Minis was out of his turret before Nish could blink and killed the struggling creature with a sword blow to the neck.

'Good work,' said Tirior, even paler. 'I don't think it got off a warning. Did you hear anything, Nish?'

'No,' he said, though he'd lifted his ear from the funnel at the first shot.

They continued. The tunnel now ran straight and level. Tirior checked a lodestone. 'We're going in the right direction, at least.'

After half an hour of low-speed movement Nish caught a whiff of bitumen. The tunnel plunged again, levelled out and the walls suddenly became black. The sandstone here was impregnated with tar.

'How do they stand it?' said Nish. The smell was unpleasantly strong.

'I don't know. Few creatures could survive in such a place.'

'I wonder what brought them here?'

'Perhaps a special kind of node,' said Minis.

'How are you going to find the node-drainer?'

'I don't think that will be difficult,' Tirior said dryly.

They pa.s.sed back into clean sandstone, though not for long. The layers of yellow stone became black-streaked, then banded with tar, and finally completely black. Ebony droplets beaded the walls. From here on they had to go more slowly, for the walls narrowed and sometimes curved in at the sides, as if they were oozing in.

'It's a wonder we haven't run into more of the enemy,' said Nish.

'Everyone who can fight would be outside, and the others have probably evacuated.'

They crept around a corner. 'It can't be far now.' Tirior studied the lines dancing on the grey plate behind her controller. 'I '

The construct stopped suddenly. Tirior jiggled her controller. Nothing happened. 'What's going on? I can't see any field at all. Minis, can you feel feel anything?' anything?'

'No, but we're getting closer. I can almost see the place in my mind's eye, as I saw it in my foretelling.'

'The scrutator must have blocked the node-drainer,' said Nish.

She shook her head. 'That would not affect us. Constructs don't use the weak field. That's why Flydd was so desperate for our support. There's something '

'What?'

'I don't know, that's the problem. It's ... a strangeness strangeness, and I don't like it.' The whine resumed. 'It's back.'

'But for how long?'

Tirior drove the construct through the winding tunnels as fast as was humanly possible. Skidding around a corner, she found a sharp, bulging bend straight ahead. Somehow she got through with no more than a sc.r.a.pe against the sides. They slid around another bend into a cavern that opened out around them. Tirior stopped.

'What is that that?' said Nish.

The cavern was full of black mist. It took a long time to make out what she was pointing at. It seemed to be a tar fountain in the middle of the floor, a low, bubbling efflorescence about knee high.

'We can go round it,' Nish said.

'There shouldn't be anything like this here,' said Tirior with a worried frown. She consulted the green gla.s.s. 'The tar seeps should be a long way away.'

'Maybe they've oozed this way.'

'Not that quickly.' She edged the construct forward. 'See the footprints. They appear to go right through it. This fountain has only just arisen.'

They went around it, but across the far side were struck by floating globules of tar that rolled down the outside of the transparent panel, leaving black trails.

'I didn't know tar floated in air,' Nish said.

'It doesn't!' Tirior muttered, grim-faced.

'What's going on?'

'We've entered the strangeness strangeness of the node-drainer. The power it's taking from the field has to end up somewhere, and where it does, reality is ... suspended.' of the node-drainer. The power it's taking from the field has to end up somewhere, and where it does, reality is ... suspended.'

'We'd better hurry,' said Nish.

'We'll be too late!' Minis cried. 'Quickly, Tirior.'

'I don't dare go any faster.'

'You're going slower all the time!'

'The field we use is weak here.'

'Shouldn't it be getting stronger as we approach the node?' said Nish.

'Constructs don't use node fields. They draw on local stress-fields which are stronger on Aachan but, unfortunately, weaker here. I'm drawing all the power I can but it's barely enough to keep us moving.'

Minis was frantic. 'Something's gone wrong, hasn't it, Tirior?'

'Terribly. The stress-field is fading by the minute.'

'Perhaps the node-drainer is draining all all the fields,' said Nish. the fields,' said Nish.

'I don't see how it could!' she said through clenched teeth. Tirior jerked the controller. The construct lurched forward, stopped, lurched again, and then the whine cut off and it fell, the base smacking against the floor.

'I don't like the sound of that,' said Tirior, picking herself up. 'We didn't crash, we splatted.'

She threw back the hatch and they climbed onto the edge. The air stank of tar. Nish jumped down.

'No!' Tirior yelled.

Too late. His feet went right through the floor. 'Aah.' He sank to his knees in black, oozing tar.