‘We need CAIP,’ Arkwright stated flatly.
‘Right. So you’d better access it somehow.’
‘I’ll need help for that,’ said Arkwright. ‘If I’m dealing with a central nervous system, instead of a CPU -’ ‘
I
can help you,’ Mum interjected. ‘I’ve been thinking: when a nerve wants to pass a signal to another nerve, it releases acetylcholine – a neurotransmitter. If we can start with that, and – I don’t know – work out a kind of chemical signal code, to get your message through -’
‘Without a projection program?’ someone said. ‘Without any kind of molecular models? How are we going to design it?’
‘As best we can,’ Mum snapped.
‘All right,’ said Dad, wearily. ‘I’ll take care of Zennor. You and Arkwright start on CAIP. You may need Ottilie’s input -’
‘No problem.’ Ottilie had a soft, precise little voice, but it seemed curiously strong and firm compared to a lot of the others. Even Firminus was beginning to sound shaky. ‘We already have some data,’ she said. ‘Jehanne’s our tissue expert. Sloan – you can take care of that toxin analysis.’
‘Right.’
‘What about the rodog?’ Arkwright was speaking. ‘He might be the best chance we have. What if he’s the ship in miniature?’
There was a brief silence. I glanced at Yestin, who was sitting right next to me. We were still in the Pen, of course; no one would let us out. Lais was with us, huddled beside Yestin. She had her arm around his shoulders. We were all three slumped against a bench unit which, because it was on wheels, had not been transformed. It remained an ordinary bench, complete with drawers full of pipettes and Petri dishes.
I knew that, occasionally, Ottilie had performed dissections on top of this bench. And I also knew that Yestin would never allow Bam to be dissected.
The rodog was now sprawled near Yestin’s feet. Its glistening flanks rose and fell as it breathed. The very fact that it was sitting there finally convinced me: Bam
was
alive. No robot dog should ever need to rest. Yet there was Bam, resting.
His master was also resting. Poor Yestin looked really sick. His colour (or lack of it) was awful. He kept sighing and sniffing. He stared dully across the room, without actually focusing on anything much. Beside him, Lais didn’t look any better.
She, too, had been given a sedative.
‘Excuse me.’ Sloan was squeezing past our feet.
Glancing up, I saw that he was carrying a piece of equipment. ‘Could I put this down here? Thanks.’
‘What is it?’ I inquired, as he placed the instrument on top of the bench.
‘Portable biosensor.’
‘What are you going to do with it?’
‘Check a sample.’ Sloan glanced over at Dygall, who had dozed off in one corner. Then he turned back to me, and lowered his voice. ‘Toxin sample,’ he added. ‘From Zennor’s face.’
‘Oh.’
I got up, then. I was feeling a bit calmer, despite the samplers that were crawling around overhead. Every few seconds I would glance at the ceiling, just to keep track of where they were.
Sloan followed my gaze.
‘They haven’t been giving
us
any trouble,’ he assured me.
‘Doesn’t mean they won’t.’
‘Possibly.’ Sloan transferred his toxin sample, inserted the slide into its slot, and powered up. ‘I’d certainly like to know what’s going on with those samplers,’ he mused. ‘They’re just overblown biosensors – or they
used
to be. Protein-based ion channels inside lipid membranes, with a metalloy/bacteriorhodopsin composite coating. So how come they’ve started squirting people with organic acid?’
‘Maybe we ought to catch one,’ I murmured, my eyes still fixed on the ceiling.
‘Maybe. I wouldn’t like to try, though. Suppose they start defending themselves?’
‘We need guns,’ someone mumbled.
It was Dygall. He was awake again. Sloan and I both looked over at where he was curled up, near a plankton tank.
He gazed back at us blearily.
‘We need guns,’ he repeated, with some effort.
‘Weapons . . .’
‘Take it easy, Dygall,’ said Sloan.
‘
Charge
guns!’
‘We can’t go letting off bursts of electromagnetic radiation,’ Sloan pointed out. His tone was distracted, because his attention was once more focused on the work in front of him. ‘It wouldn’t be safe.’
‘Safe?’ squawked Dygall, and coughed. ‘
Safe?
What are you
talking
about, you idiot? This whole ship’s probably going to collapse any minute!’
‘Not necessarily.’
‘We’re in
space
! Living things can’t
survive
in space!’
‘This one was designed to.’ Sloan adjusted something on his biosensor, speaking gently. ‘Anyway, there are some pretty tough organisms around, remember. We’ve used them ourselves.’
‘What’s the
matter
with you?’ Dygall protested. ‘Are you crazy? Can’t you see what’s happened? People are dying!’
‘Hey.’ I went over to Dygall. He was my Little Brother, after all. ‘Do you want a bite to eat?’ I asked, crouching next to him. ‘We can still use the food dispenser. Peanuts and things – Ottilie’s tested them out on the germinators.’
‘Cheney . . .’ His eyes filled with tears. ‘My dad’s dead,’ he whispered.
‘I know.’ What could I do? I squeezed his arm. ‘I’m so sorry, Dygall.’
‘We’re all dead.’
‘No.’
‘We’re all going to die,’ he insisted, and laughed. It was a terrible laugh. Like something breaking.
‘Dygall, we’re still alive,’ I said. ‘We won’t be if we lose it. You know? We can’t afford to lose it. We just can’t.’
He blinked at me, and swallowed. I think he might have nodded. I’m not sure, though, because at that moment I was distracted by Mum and Arkwright, who had entered the room to look for Yestin’s rodog.
‘There it is,’ said Arkwright – but he hesitated. So did Mum. They were studying Yestin.
He didn’t seem to notice them, until Mum hunkered down in front of him.
‘Yestin?’ she murmured. ‘Honey? We need to do something.’
My teeth were clenched; I was waiting for the explosion. Yestin was obsessed with that rodog. I was sure that he would never allow anyone to harm it.
But I was wrong. The explosion didn’t come. Yestin just gazed blankly, nodding and shrugging, as Mum explained what had to be done. I was wondering if he even understood – if the news was even sinking in – when Dad reappeared.
He began to search through the drawers in the bench.
‘What’s this?’ he asked Sloan, pulling out a long, flexible tube.
Sloan flicked a glance at him. ‘Spare pipe for the hydroliser.’
‘And these?’
‘I think that’s a set of electrodes for plasma arcing.’
‘What about this?’
‘Vacuum valve seal.’
‘What are you doing, Dad?’ I couldn’t understand the point of his questions.
It took him a moment to find me, down on the floor. When he did, he said, ‘We need to get hold of a sampler. Firminus and I are trying to devise some sort of trap.’
‘Oh.’ That made sense, I suppose. Then Dygall stirred beside me.
‘You shouldn’t be building traps,’ he hoarsely remarked.
‘You should be building
weapons
.’
Dad dropped something, at that point, and it broke when it bounced off the bench-leg; I heard the tinkling noise. Dad cursed, and stooped to pick up the pieces. It was Sloan who answered Dygall.
‘Stop and think,’ he said quietly, turning his smooth, vivid face towards my Little Brother. ‘If we damage this ship, we’ll damage ourselves. We can’t treat Plexus as an enemy.
We have to
help
it, not hurt it. Or we haven’t got a chance.’
‘But -’
‘He’s right, Dygall.’ Dad had straightened. ‘I know it’s hard, but we can’t let our emotions get the better of us.’
‘It’s all right for
you
,’ Dygall spat. ‘You’re still – you didn’t – my Dad’s
dead
. . .’ If he hadn’t been sedated, he probably would have screamed these words. As it was, he muttered them, and moved away from Lais when she tried to hug him.
Meanwhile, Arkwright had picked up Bam. He said, ‘You might want to do the examination in here, Quenby.’
‘Yes,’ said Mum. She rose, pulling Yestin up with her. ‘You kids, could you go back into the other room, now? It’s . . . um . . .’
‘Clear,’ Arkwright finished.
‘Yes. It’s clear, in there.’ She meant, I suppose, that Zennor’s body had been hidden away. In the precision pipe, or whatever it was. Before we could move, however, Sloan suddenly said, ‘There’s a high concentration of nitric acid in this toxin sample.’
Everyone stared at him. He pointed at a glowing panel on top of his biosensor.
‘Check for yourselves,’ he continued. ‘It’s not the nastiest component, by any means, but it’s the largest.’ When no one had any comment to make, he added, ‘Which suggests that there might be rather a lot of nitric oxide floating around on this ship, somewhere. Unfortunately.’
‘Nitric oxide?’ Mum echoed.
‘Correct me if I’m wrong,’ said Dad, ‘but isn’t nitric acid highly corrosive?’ He waved a small metal drum. ‘I mean, even if we built some sort of suction pump, and trapped one of those samplers in this filter canister -’
‘It might work its way out,’ Sloan finished. ‘Yes.’
‘Shit.’
‘But there should be some way of neutralising the acid,’ Sloan went on thoughtfully. ‘I mean, we can
use
the fact that those things are alive. We could start at the molecular level, with something that will inhibit protein synthesis or dissolve peptide bonds. Like interferon, for example. Though we haven’t got CAIP to do the cytanalysis, of course -’
‘Wait. Wait a second.’ Mum flapped her left hand at Sloan. Her right hand was clamped across her forehead. ‘Nitric oxide.
Nitric oxide
.’
We all waited.
‘We synthesise our
own
nitric oxide. Every one of us! In our bodies! Peroxide, superoxide, lectoferrin . . .’ She counted them off on her fingers. ‘And nitric oxide! The neutrophils manufacture it to destroy free radicals!’
A few questioning glances were exchanged. Only Sloan seemed to understand what was going on. He stared hard at my mother with narrowed eyes.
‘What are neutrophils?’ Lais asked cautiously.
‘White blood cells!
White blood cells,
Lais!’
Sloan lifted his face, and scanned the ceiling. ‘Those samplers were manufactured to detect impurities,’ he conceded slowly. ‘After which they’re supposed to signal for a clean-up . . .’
‘Wait just a minute.’ Dad’s voice was tight. ‘Quenby, are you saying – are you saying those samplers are part of the ship’s
immune system
?’
I gasped. Once again, my mind was flooded with ideas, which came together like chemical reagents, sparking other ideas. It all made instant sense. I had studied the immune system at school, and remembered how it worked: the first line of defence (skin, mucous, nose hairs), the increase of local temperature (to speed up cell production), the swelling of blood vessels in the brain, the constriction of blood vessels in the skin – and the armies of immune cells. Some of these cells were produced in the bone marrow, some in the lymph nodes. Leucocytes, they were called – white blood cells.
They killed things. Bacteria. Viruses. Foreign bodies of any kind. They were
designed
to kill things.
‘But we’re not foreign bodies!’ I burst out. ‘We’ve lived here all our lives!’
‘Shh,’ said Dad. ‘Don’t panic . . .’
‘Cheney’s right,’ Sloan agreed, frowning. For the first time, he looked worried. ‘We’re like the bacteria in our own gut. We’re part of this system, we always have been. How can we have been identified as a threat?’
‘Maybe it was me,’ said Arkwright faintly. He cast his eyes around the room. ‘I popped that sub-conduit. On the Bridge.’
‘Oh, but we patched that up.’ Mum’s voice shook. ‘We fixed it, Arkwright.’
‘Yes, but suppose someone else didn’t?’ I had remembered the Remote Access Repair Units. The hydrochloric acid. I spoke before even stopping to think. ‘Suppose someone saw one of the RARs attacking the struts, and threw something at it? There are so many people on board. If just one of us panicked . . .’
I couldn’t finish. Sloan was regarding me gravely. Lais had buried her face in her hands. Arkwright swore as Bam wriggled free of his grasp and bounded towards the door.
Before the fleeing rodog even reached it, however, someone cried out. From the other room.
Someone who sounded absolutely terrified.
‘Oh
no
!’ he shouted. ‘Look!
Oh no!
’
The smell was the first thing we noticed as we poured out of the Pen. It was a terrible smell that made us all cough: a smell of burning meat, with another stench overlaying it. Then we saw Firminus standing by the door.
He pointed.
‘Something’s trying to get in,’ he rasped.
Where the two fleshy panels met, the door was changing colour from pink to brown. Bits of it were sloughing away, in yellow-and-red streaks. A pale vapour poured off the dissolving tissue.
‘Acid,’ said Sloan.
‘But – but it can’t be!’ This was Lais. ‘They can’t be attacking the fabric of the
ship
!’
‘NK cells,’ Mum croaked.
‘What?’
‘Natural Killer cells.’ Mum couldn’t take her eyes off the door. Her voice sounded dull. ‘If there’s a virus inhabiting an ordinary cell, an NK cell binds to it and releases chemicals which destroy the cell membrane, so that the cell bursts open.’
‘Holy mother of God,’ said Ottilie. I froze up. I couldn’t think. Natural Killer cells?
Natural Killer cells
?
We didn’t stand a chance.
‘We have to get out.’ Dad grabbed my arm. He was scanning the room. ‘How can we get out?’
‘We can’t!’ Lais wailed.
‘Yes we can.’
It was Dygall. He seemed remarkably calm – perhaps because he was still sedated.
‘The air ducts,’ he declared.
The air ducts! Yes! I peered up, searching for the access panel. Because we were on A deck, the air duct ran overhead. It ran between A and B decks, along with the filtration ducts and cable conduit. You could reach it through access panels, or through hatches in the stair shafts that could be found at both ends of every street.