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.
Vicuna fired. Perhaps I had underestimated the skill that it would take to seriously incapacitate someone even when they stood so close, for the doctor’s slug only hit Rodriguez in the shoulder of his other arm, causing him to stagger back and grunt, but no more than that. Rodriguez’s gun flashed and the doctor fell backwards into the mulch.
On the edge of the clearing, Cahuella shrugged off his rifle and was on the point of bringing it to bear.
‘No!’ I started to shout, willing my master to save himself by getting as far away as possible from Rodriguez, but — as I belatedly realised — Cahuella was not the kind to walk away from a fight, even one in which his own life might be contested.
Gitta screamed for her husband to follow her.
Rodriguez levelled the gun towards Cahuella and fired…
And missed, his slug slicing through the bark of a nearby tree.
I tried to find some sense in what was happening, but there was no time. Vicuna appeared to have been correct. Everything that Rodriguez had done in the last few moments was consistent with the ghoul’s statement… which meant that Rodriguez was — what?
An impostor?
‘This is for Argent Reivich,’ Rodriguez said, drawing his aim again.
This time, I knew, he would not miss.
I raised the monofilament scythe, thumbed the invisibly fine cutting thread to its maximum, piezo-electrically maintained length: a hyper-rigid mono-molecular line extending fifteen metres ahead of me.
Rodriguez, out of the corner of his eye, caught what I was about to do, and made the one mistake which marked him as an amateur, rather than a professional assassin.
