The Revelation Space Collection (141 page)

They were rare, but distributed across a large area of the Peninsula. It was that very rarity which had made them the focus of early attention, for the trees were conspicuously different to the other forest species. Each rose to the height of the canopy and no higher - forty or fifty metres above the forest floor, depending on the surrounding growth. Each was shaped like a spiral candlestick, thickening towards the base. Near the top, the trees flared into a wide, flattened structure like a dark green mushroom, tens of metres across. It was these mushrooms which had made the hamadryad trees so obvious to the first explorers, overflying the jungle in one of the Santiago’s shuttles.

Now and then they found a clearing near a tree and set down to investigate on foot. The biologists amongst them had struggled to find an explanation for the trees’ shapes, or the strange differentiation in cell types which occurred around the tree’s perimeter and along radial lines through it. What was clear was that the wood at the heart of the trees was dead growth, with the living matter existing in a relatively thin layer around the husk.

The spiral candlestick analogy was accurate up to a point, but a better description, I felt, was of an enormously tall and thin helter-skelter, like the dilapidated old one I remembered from an abandoned fairground in Nueva Iquique, its pastel blue paint peeling away a little more with each summer. The tree’s underlying shape was more or less a tapering cylindrical trunk, but wrapped around this, ascending to the summit, was a helical structure whose spirals did not quite lie in contact with each other. The helix was smooth, patterned in geometric brown and green shapes which shimmered like beaten metal. In the gaps where the underlying trunk was visible, there was often evidence for a similar structure which had been worn down or absorbed into the tree, and perhaps levels of structure behind that too, though only a skilled botanist really had the eye to read those subtleties of tree growth.

Dieterling had indentified the major spiral around this tree. At the base, just where it looked as if the spiral ought to plunge into the ground like a root, it terminated in a hollow opening.

He pointed it out to me. ‘It’s hollow almost all the way to the top, bro.’

‘Meaning what?’ Rodriguez said. He knew how to handle the juvenile, but he was no expert on the creatures’ biological cycle.

‘Meaning it’s already hatched,’ Cahuella said. ‘The juveniles from this one have already left home.’

‘They eat their way out of their mother,’ I said. We still had no idea whether there were distinct hamadryad sexes, so it was entirely possible that they had eaten their way out of their father as well - or neither. When the war was over, probing hamadryad biology would fuel a thousand academic careers.

‘How big would they have been?’ Gitta asked.

‘As big as our own juve,’ I said, kicking the maw at the base of the spiral. ‘Maybe a touch smaller. But nothing you’d want to meet without some heavy firepower.’

‘I thought they moved too slowly to pose us any threat.’

‘That’s the near-adults,’ Dieterling said. ‘And even then, you wouldn’t necessarily be able to out-run it - not through overgrowth like this.’

‘Would it want to eat us - I mean, would it even recognise us as something to be eaten?’

‘Probably not,’ Dieterling said. ‘Which might not be much consolation as it slithers over you.’

‘Ease off it,’ Cahuella said, putting a hand round Gitta. ‘They’re like any wild animal - only dangerous if you don’t know what the fuck you’re doing. And we do know, don’t we?’

Something crashed through the overgrowth behind us. Startled, we all turned around, half expecting to see the eyeless head of a near-adult bearing down on us like a slow-moving freight train, crunching through the jungle which impeded its implacable slithering progress about as efficiently as fog.

Instead, what we saw was Doctor Vicuna.

The doctor had shown no inclination to follow us when we had left camp, and I wondered what had made him change his mind. Not that I was in any way glad of the ghoul’s company.

‘What is it, Doctor?’

‘I became bored, Cahuella.’ The doctor high-stepped through what remained of the overgrowth I had scythed. His clothes, as usual, were impeccable, even as ours picked up cuts and stains from the time in the field. He wore a knee-length dun field jacket, unzipped at the front. Around his neck dangled a pair of dainty image-amp goggles. His hair was kiss-curled, lending him the sordid air of a malnourished cherub. ‘Ah - and this is the tree!’

I stepped out of his path, my hand sweating around the haft of the monofilament scythe, imagining what it would do to the ghoul if I were to accidentally extend the cutting arc and flick it through him. Whatever pain he suffered in the process, I thought, could not be measured against the cumulative dose he had inflicted in his career.

‘Quite a specimen, isn’t it,’ Cahuella said.

‘The most recent fusion probably only happened a few weeks ago,’ Dieterling said, as comfortable with the ghoul as his master. ‘Take a look at the cell-type gradient here.’

The doctor ambled forward to see what Dieterling was talking about.

Dieterling had unpacked a slim grey device from the waist pocket of his hunting jacket. Of Ultra manufacture, it was the size of an unopened Bible, set with a screen and a few cryptically marked controls. Dieterling pressed one side of the device to the helix and thumbed one of the buttons. In shades of pale blue, vastly magnified cells appeared on the screen. They were hazy cylindrical shapes, packed together haphazardly like body bags in a morgue.

‘These are essentially epithelial cells,’ Dieterling said, sketching a finger across the image. ‘Note the soft, lipid structure of the cell membrane - very characteristic.’

‘Of what?’ Gitta said.

‘Of an animal. If I took a sample of your liver lining, it wouldn’t look too dissimilar to this.’

He moved the device to another part of the helix, a little closer to the trunk. ‘Now look. Totally different cells - arranged much more regularly, with geometric boundaries locked together for structural rigidity. See how the cell membrane is surrounded by an additional layer? That’s basically cellulose.’ He touched another control and the cells became glassy, filled with phantom shapes. ‘See those podlike organelles? Nascent chloroplasts. And those labyrinthine structures are part of the endoplasmic reticulum. All these things are defining characteristics of plant cells.’

Gitta tapped the bark where Dieterling had made the first scan. ‘So the tree is more like an animal here, and more like a plant - here?’

‘It’s a morphological gradient, of course. The cells in the trunk are pure plant cells - a cylinder of xylem around a core of old growth. When the snake first attaches itself to the tree, wrapping around it, it’s still an animal. But where the snake comes into contact with the tree, its own cells begin to change. We don’t know what makes that happen - whether the triggering cue comes from something in the snake’s own lymphatic system, or whether the tree itself supplies the chemical signal to begin fusion.’ Dieterling indicated where the helix merged seamlessly with the trunk. ‘This process of cellular unification would have taken a few days. When it was over, the snake was inseparably attached to the tree - had, in fact, become part of the tree itself. But most of the snake was still an animal at that point.’

‘What happens to its brain?’ Gitta asked.

‘It doesn’t need one anymore. Doesn’t even need anything we’d exactly recognise as a nervous system, to be frank.’

‘You haven’t answered my question.’

Dieterling smiled at her. ‘The mother’s brain is the first thing that the juveniles eat.’

‘They eat their mother?’ Gitta said, horrified.

The snakes merged with their host trees, becoming plants themselves. It only happened when the snakes were in their near-adult phase, large enough to spiral around the tree all the way from the ground to the canopy. By then young hamadryads were already developing in what passed for the creature’s womb.

The host tree had almost certainly already seen several fusions. Perhaps the original, true tree had long since rotted away, and what remained were only the locked spirals of dead hamadryads. It was likely, however, that the last snake to attach itself to the tree was still technically alive, having spread its photosynthetic cowl wide from the top of the tree, drinking sunlight. No one knew how long the snakes could have lived in that final brainless plant-phase. What was known was that another near-adult would arrive sooner or later and claim the tree for itself. It would slither up the tree and force its head through the cowl of its predecessor, then spread its own cowl over the old. Deprived of sunlight, the shadowed cowl would wither away quickly. The newcomer would fuse with the tree, becoming mostly plant. What little animal tissue remaining was there only to supply the young with food, born within a few months of the fusion. Some chemical trigger would cause them to eat their way out of the womb, digesting their mother as they went. Once they had eaten her brain, they would chew their way down the spiral length of her body, until they emerged at ground-level as fully formed, rapacious juvenile hamadryads.

‘You think it’s vile,’ Cahuella said, reading Gitta’s thoughts expertly. ‘But there are life-cycles amongst terrestrial animals which are just as unpleasant, if not more so. The Australian social spider turns to mush as her spiderlings mature. You have to admit it has a kind of Darwinian purity to it. Evolution doesn’t greatly care about what happens to creatures once they’ve passed on their genetic heritage. Normally adult animals have to stick around long enough to raise their young and safeguard them from predators, but hamadryads aren’t constrained by those factors. Even juveniles are nastier than any other indigenous animals, which means there’s nothing to protect them against. And they don’t need to learn anything they don’t already have hardwired into them. There’s almost no selection pressure to prevent the adults from dying the instant they’ve given birth. It makes perfect sense for the juveniles to gorge themselves on their mothers.’

It was my turn to smile. ‘You almost sound like you admire it.’

‘I do. The purity of it - who couldn’t admire that?’

I am not sure quite what happened then. I was looking at Cahuella, with half an eye on Gitta, when Vicuna did something. But the first flash of movement seemed to have come not from Vicuna but from my own man Rodriguez.

Vicuna had reached into his jacket and pulled out a gun.

‘Rodriguez,’ he said. ‘Step away from the tree.’

I had no idea what was happening, but I saw now that Rodriguez’s own hand was buried in his pocket, as if he had been on the point of reaching for something. Vicuna waggled the end of his gun emphatically.

‘I said step away.’

‘Doctor,’ I said, ‘would you mind explaining why you are threatening one of my men?’

‘Gladly, Mirabel. After I’ve dealt with him.’

Rodriguez looked at me, eyes wide in what looked like confusion. ‘Tanner, I don’t know what he’s on about. I was just going for my rations pack . . .’

I looked at Rodriguez, then at the ghoul.

‘Well, doctor?’

‘He has no rations pack in that pocket. He was reaching for a weapon.’

It made no sense. Rodriguez was already armed - he had a hunting rifle slung over one shoulder, just like Cahuella.

The two of them faced each other, frozen.

I needed to make a decision. I nodded at Cahuella. ‘Let me handle this. Get yourself and Gitta away from here; away from any possible line of fire. I’ll meet you back at the camp.’

‘Yes!’ Vicuna hissed. ‘Get away from here, before Rodriguez kills you.’

Cahuella took his wife and stepped hesitantly away from the tableau. ‘Are you serious, doctor?’

‘He seems adequately serious to me,’ Dieterling murmured. He was already edging away himself.

‘Well?’ I said, towards the ghoul.

Vicuna’s hand was trembling. He was no gunman - but no kind of marksmanship would have been necessary to take out Rodriguez at the distance that spaced them. He spoke slowly and with forced calm. ‘Rodriguez is an impostor, Tanner. I received a message from the Reptile House while you were here.’

Rodriguez shook his head. ‘I don’t need to listen to this!’

I realised that it was entirely possible that he had received some kind of message from the Reptile House. Normally I snapped on a comms bracelet before I left camp, but I had forgotten it in my haste this morning. Someone calling from the House would only have been able to get as far as the camp.

I turned to Rodriguez. ‘Then take your hand slowly out of your pocket.’

‘Don’t tell me you believe the bastard!’

‘I don’t know what I believe. But if you’re telling the truth, all you’ve got in there is a rations pack.’

‘Tanner, this is—’

I raised my voice. ‘Just do it, damn you!’

‘Careful,’ Vicuna hissed.

Rodriguez drew his hand from the pocket with magisterial slowness, glancing to myself and then Vicuna all the while. What came out, gripped between thumb and forefinger, was slim and black. The way he held it, in the perpetual gloom of the forest floor, it was almost possible to believe it was a rations pack. For a moment I did.

Until I saw that it was a gun, small and elegant and vicious; engineered for assassination.