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-glass 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, 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. 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 passed 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 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, 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 scrape against the sides. They slid around another bend into a cavern that opened out around them. Tirior stopped.
‘What is 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 glass. ‘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 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 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.
Cursing him, Tirior reached down. Nish took her hand. She tried to pull him out. He did not budge.
‘Give me a hand,’ she shouted at Minis, who had his hands over his face and was rocking on the rim. ‘Minis, now!’