equilibrium. I’m not sure how the deflation happens, except that it’s something to do with changing the piezoelectric current in the tubes.’
‘I still don’t see why Gilgamesh needs it.’
‘Think. If you can get a sample of this to Ganymede, they might be able to find a way of attacking it. All you’d need would be a molecular agent capable of opening the gaps between the fullerene strands so that a molecule of water could squeeze through, or something that impedes the piezoelectric force.’
Absently Vargovic watched a squid-like predator nibble a chunk from the bag of a ventling. The squid’s blood ran thick with two forms of haemoglobin, one oxygen-bearing, one tuned for hydrogen sulphide. They used glycoproteins to keep their blood flowing and switched metabolisms as they swam from oxygen-dominated to sulphide-dominated water.
He snapped his attention back to Cholok. ‘I can’t believe I came all this way for… what? Carbon?’ He shook his head, slotting the gesture into the primary narrative of their conversation. ‘How did you obtain this?’
‘An accident, with a gilly.’
‘Go on.’
‘An explosion near one of the bubbles. I was the surgeon assigned to the gilly; had to remove a lot of hyperdiamond from him. It wasn’t difficult to save a few splinters.’
‘Forward-thinking of you.’
‘Hard part was persuading Gilgamesh to send you. Especially after Maunciple—’
‘Don’t lose any sleep over him,’ Vargovic said, consulting his coffee. ‘He was a fat bastard who couldn’t swim fast enough.’
The surgery took place the next day. Vargovic woke with his mouth furnace-dry.
He felt… odd. They had warned him of this. He had even interviewed subjects who had undergone similar procedures in Gilgamesh’s experimental labs. They told him he would feel fragile, as if his head was no longer adequately coupled to his body. The periodic flushes of cold around his neck only served to increase that feeling.
‘You can speak,’ Cholok said, looming over him in surgeon’s whites. ‘But the cardiovascular modifications — and the amount of reworking we’ve done to your laryngeal area — will make your voice sound a little strange. Some of the gilled are really only comfortable talking to their own kind.’
He held a hand before his eyes, examining the translucent webbing that now spanned between his fingers. There was a dark patch in the pale tissue of his palm: Cholok’s embedded sample. The other hand held another.
‘It worked, didn’t it?’ His voice sounded squeaky. ‘I can breathe water.’
‘And air,’ Cholok said. ‘Though what you’ll now find is that really strenuous exercise only feels natural when you’re submerged. ’
‘Can I move?’
‘Of course,’ she said. ‘Try standing up. You’re stronger than you feel.’
He did as she suggested, using the moment to assess his surroundings. A neural monitor clamped his crown. He was naked, in a brightly lit revival room; one glass-walled side faced the exterior ocean. It was from here that Cholok had first contacted Gilgamesh.
‘This place is secure, isn’t it?’
‘Secure?’ she said, as if the word itself was obscene. ‘Yes, I suppose so.’
‘Then tell me about the Denizens.’
‘What?’
‘Demarchy codeword. Cryptanalysis intercepted it recently — supposedly something about an experiment in radical bio-modification. I was reminded of it in the aquarium.’ Vargovic fingered the gills in his neck. ‘Something that would make this look like cosmetic surgery. We heard the Demarchy had tailored the sulphur-based metabolism of the ventlings for human use.’
She whistled. ‘That would be quite a trick.’
‘Useful, though — especially if you wanted a workforce who could tolerate the anoxic environments around the vents, where the Demarchy happens to have certain mineralogical interests.’
‘Maybe.’ Cholok paused. ‘But the changes required would be beyond surgery. You’d have to script them in at the developmental level. And even then… I’m not sure that what you’d end up with would necessarily be human any more.’ It was as if she shivered, though Vargovic was the one who felt cold, still standing naked beside the revival table. ‘All I can say is, if it happened, no one told me.’
‘I thought I’d ask, that’s all.’
‘Good.’ She brandished a white medical scanner. ‘Now can I run a few more tests? We have to follow procedure.’
Cholok was right: quite apart from the fact that Vargovic’s operation was completely real — and therefore susceptible to complications that had to be looked for and monitored — any deviation from normal practice was undesirable.
After the first hour or so, the real strangeness of his transformation hit home. He had been blithely unaffected by it until then, but when he saw himself in a full-body mirror, in the corner of Cholok’s revival room, he knew that there was no going back.
Not easily, anyway. The Gilgamesh surgeons had promised him they could undo the work — but he didn’t believe them. After all, the Demarchy was ahead of Ganymede in the biosciences, and even Cholok had told him reversals were tricky. He’d accepted the mission in any case: the pay tantalising; the prospect of the sulphur projects rather less so.
Cholok spent most of the day with him, only breaking off to talk to other clients or confer with her team. Breathing exercises occupied most of that time: prolonged periods spent underwater, nulling the brain’s drowning response. Unpleasant, but Vargovic had done worse things in training. They practised fully submerged swimming, using his lungs to regulate buoyancy, followed by instruction about keeping his gill-openings — what Cholok called his opercula — clean, which meant ensuring the health of the colonies of commensal bacteria that thrived in the openings and crawled over the fine secondary flaps of his lamellae. He’d read the brochure: what she’d done was to surgically sculpt his anatomy towards a state somewhere between human and air-breathing fish: incorporating biochemical lessons from lungfish and walking-catfish. Fish breathed water through their mouths and returned it to the sea via their gills, but it was the gills in Vargovic’s neck that served the function of a mouth. His true gills were below his thoracic cavity: crescent-shaped gashes below his ribs.
‘Compared to your body size,’ she said, ‘these gill-openings are never going to give you the respiratory efficiency you’d have if you went in for more dramatic changes—’
‘Like a Denizen?’
‘I told you, I don’t know anything about that.’
‘It doesn’t matter.’ He flattened the gill-flaps down, watching — only slightly nauseated — as they puckered with each exhalation. ‘Are we finished?’
‘Just some final bloodwork,’ she said, ‘to make sure everything’s still functioning properly. Then you can go and swim with the fishes.’
While she was busy at one of her consoles, surrounded by false-colour entoptics of his gullet — he asked her, ‘Do you have the weapon?’
Cholok nodded absently and opened a drawer, fishing out a hand-held medical laser. ‘Not much,’ she said. ‘I disabled the yield-suppresser, but you’d have to aim it at someone’s eyes to do much damage.’
Vargovic hefted the laser, scrutinising the controls in its contoured haft. Then he grabbed Cholok’s head and twisted her around, dousing her face with the laser’s actinic-blue beam. There were two consecutive popping sounds as her eyeballs evaporated.
‘What, like that?’
Conventional scalpels did the rest.
He rinsed off the blood, dressed and left the medical centre alone, travelling kilometres down-city, to where Cadmus-Asterius narrowed to a point. Even though there were many gillies moving freely through the city — they were volunteers, by and large, with full Demarchy rights — he did not linger in public for long. Within a few minutes
