I stepped back, trying to perceive an order to the collection. In the centre a grey stone fireplace housed a copper alembic with a spout, resting on a little earthenware furnace with a bellows handle projecting. It was for fraction-distilling aromatic oils. The lintel above it bore the deeply incised and gilded legend: ‘Observe nature, your only teacher.’

I looked at the anatomical preparations: dense white shapes in jars, organs folded, wrinkled or bulging, or feathery and delicate like branching lungs. Alcohol preserved specimens like paperweights, of this or that organ in sagittal or cross section. Living with these, Rayne must see people as machines, nothing but arrangements of tissues and liquids, interesting puzzles to solve. She also knows that individuality is mostly skin-deep because, inside, people are all the same. Rayne and Frost, I reflected, had many traits in common.

Her reference collection was ordered by pathology. Some samples were hundreds of years old-the only immortality available to Zascai by virtue of their interesting ailments. The sufferers usually readily agree to be preserved; it’s all one to them whether their useless remains are placed in the ground or in a jar. The only exception are Awians, who prefer to be interred in tombs as florid as they can afford, as if they want to take up space forever.

A glass case housed a collection of surgical instruments past and present-steel bone saws and silver catheters, water baths for small dissections. Rayne kept some-like cylindrical saw-edged trepanning drills and equipment for cupping and blood letting-to remind the world of the doctors’ disgusting practices to which she put an end when she joined the Circle.

A six-fingered hand, a flaky syphilitic skull. A hydrocephalic one five times normal size, and the skeleton of a man with four wings growing out of his chest.

Rayne uses me in demonstrations when I’m available. I pose at the front of the auditorium while she lectures the students on how weird I am, or on her great achievement in healing my Slake Cross injuries. One day my skeleton might stand here to be prodded by subsequent generations, my strong, gracile fingers adapted for climbing, my curve-boned wings articulated to stretch full length to their pointed phalanges.

Beside the door I’d come in by stood a large showcase of chipped stone arrowheads, which Rayne had arranged into an attractive pattern. She buys them for a few pence each from boys who pick them up on the Awndyn Downs. There was also a ‘piece of iron that fell from the sky onto Shivel’. On the other side of the door a skeleton inhabited a tall cabinet; its label said: ‘Ancient Awian, from a cave in Brobuxen, Ressond’.

Over two thousand years the grey smell of old bone and neat alcohol had saturated the tower’s very fabric. It was a haze of carbolic and formalin. Spicy volatile notes of orange and clove must be the essential oils Rayne had most recently prepared.

I examined the labelled majolica jars: oenomel, rodomel and hippocras; storax, orchis and sumac. Patent medicines crusted or deliquesced in slipware pots. Their names skipped off the tongue like a schoolyard rhyme: Coucal’s Carminiative Embrocation; Popinjay Pills for Pale People; Ms Twite’s Soothing Syrup; Cornstock Electuary; Emulsion Lung Tonic; World-Famed Blood Mixture; Dr Whinchat of Brandoch’s Swamp-root Kidney Cure; Fruit Salt; Spa Mud; Abortion Lotion; Concentrated Essence of Cinnamon for Toothache; Confection of Cod Livers; Balsamic Elixir for Inflamed Nipples; Bezon & Bro. Best Beet Juice. A pot with a spout: Goosander Lewin’s Improved Inhaler. Preparation of Bone Marrow: an Ideal Fat Food for Children and Invalids; Odiferous Macassar for Embellishing the Feathers and Preventing Them Falling Out.

‘I’ doesn’ work,’ Rayne said.

‘What, any of it?’ I asked, but I turned and saw she was referring to the atropine, which her servant had brought, and she had mixed a miniscule amount with the water drops she was squeezing into Cyan’s mouth. ‘This should work. Why doesn’ i’?’ she said, annoyed. ‘I’ brings you round, on t’ times I try i’ wi’ you. I daren’ give her more than this. Do you know how much she took?’

‘No…’ I suddenly remembered I had the wrap in my pocket. I stopped moping around the museum and joined her in the bedroom. ‘But I can assay it. I picked up her scolopendium from the barge.’

‘Of course, you would.’

I sighed. ‘Just don’t let me put my fingers in my mouth.’ I cautiously brought out the wrap-the sight of it triggered my craving and damp sprang up on the palms of my hands. Truly we are nothing but chemicals.

‘Don’ give in,’ said Rayne, over her shoulder.

I pinched the bridge of my nose. ‘I…I can’t…’

‘So you’ll give in? Think of t’ disadvantages-look a’ her! Remember how bad you feel for six months after kicking. You’re doing well now; each time you ge’ clean i’s for slightly longer. The balance has tipped.’

I calmed myself, thinking; no one is asking me to do without it permanently. I said, ‘It’s cooked at source somewhere in Ladygrace. But is it cut?’

The rounded hills of Ladygrace, where scolopendium fern grows, have that name because as you approach from a distance their profile looks like a voluptuous woman lying on her back with her knees in the air. The most difficult part of the route is shipping the finished product across the Moren estuary. It never occurred to me, when I was ripping off Dotterel’s shop and selling at the wharves, how much more money I could have made smuggling by air.

I poured water into another glass and delicately shook the paper over it. Grains fell out and dissolved on impact with the surface, leaving no residue. Even the largest had gone before it fell half a centimetre through the water column.

‘Shit, it’s pure. Maybe eighty to ninety per cent…If I hadn’t used for a while I wouldn’t shoot this.’

Rayne said, ‘If Cyan was buying, I think she could prob’ly afford pure.’

‘That’s what killed Sharny. He wouldn’t have been used to it. He didn’t even have time to take the tourniquet off…’ I imagined him thinking-some bastard’s cut this-then the fact it isn’t cut hits with full strength. His hands clench, he struggles for breath but it’s clear there won’t be a next one.

Feeling suddenly nauseous I dumped it in the fire and wiped my hands. ‘It’d lay me out.’

‘For how long?’

‘A day and a half. Is she likely to die?’

‘I can’ tell. But if she does i’s no’ my faul’.’

‘I’m fucked. What will Saker do when I tell him his only daughter is in a coma from a massive overdose? I’m the only junky he knows. He’ll shoot me!’

‘Mmm.’

‘When I first saw her I drooled like a dog on a feast day. I thought she was feek! She was a mink!’ I ran out of slang and just scooped a feminine body out of the air with a couple of hand movements. ‘But now she looks like a corpse! They called it jook, not cat, or I would have known!’

We called the stuff cat because it makes you act like one, roaming all night on the buzz at first, then languid and prone to lying around.

‘Did you jus’ throw i’ all away?’

‘Yes.’

The night wore on, mercilessly. I put on the clothes the servant had found for me, though they were not svelte enough to fit-I have to have clothes made to measure-and the shirt was red. Red is not my colour at all. I ate some bread, but it didn’t cure my hangover. The liquor settled in my gut, leaching water from my body and diluting it. The water I drank turned straight into piss and I was still so dehydrated my tongue clacked on the roof of my mouth like a leather strap. I felt as if my skin was drying; my fingertips were wrinkled and a headache like a steel band tightened round my temples. My heartbeat shook my whole body, and I scarcely knew what to do with my hands.