All around, on the floor and crowded onto tables and shelves, on top of narrow plinths, in the window ledges, there were animals in different poses: down on all fours or up on hind legs, calmly perched on branches or clawing at the bark with wings spread mid-flap, species both docile and baring their teeth. Some were only half complete and showed the wire construction in their chests and the hessian stuffing in their backs, their small, brown featherless wings and empty eye sockets waiting for coloured glass beads. It seemed business was solid for Hugh Alfred Collins.

Rolt walked through the silent animals. The dusty room felt poised, or frozen. He noted a number of rare species, including a Platypus anatinus, labelled with a tag on its webbed foot. He stopped before the strange creature, no more than a foot long.

‘You’re aware that Blumenbach named it Ornithorhynchus paradoxus, which is now the accepted designation?’ Rolt asked. ‘Has been for some time.’

‘Of course a Prussian would say that,’ Hugh Collins said, coming out from behind a worktable. There were red-and-yellow-feathered birds laid out there, surrounded by various hand tools, spools of thread and bowls of paste, brown bottles and vials of yellow-coloured liquid, a tin half filled with pellets. ‘But I believe our Mr Shaw was first, Herr Rolt. One should always accept defeat graciously.’

Hugh Collins was lanky, broad-shouldered, a man of some thirty years. His sleeves were rolled up to the elbows, revealing large hands and hairy forearms wound in bulging veins, a man who might have swung a blacksmith’s hammer rather than sit hunched over shot punctures in hummingbirds, delicately plugging them with cotton and resin. He wiped each of his fingers separately with a rag, then held out his hand.

Rolt shook his head. ‘Let’s not spread the arsenic around.’

‘A little never hurt anybody.’ Collins smiled and cracked his knuckles.

‘Your work has become much finer, more expressive. Congratulations.’

‘And priced accordingly, my friend.’

‘How much for heads?’ Rolt said.

Collins leaned back against the edge of the workbench. ‘What sort?’

‘Human. Shrunken.’

‘Oh, righto then.’ He crossed his arms. ‘Well, there have been a few coming in from South America and the South Pacific lately. And from New Zealand now, too, or so they tell me.’

‘You haven’t come across any?’

Collins grimaced. ‘One or two. Bloody awful things.’

Rolt extracted a small card from his pocket, the name of his hotel written there, and held it out to the taxidermist. ‘You’ll inform me?’

‘Of course,’ Collins said. ‘But you know, they’re already faking them. Dead whores from St Giles sold as South Pacific warriors named Akoni. Once they’re dried and sewn up, they’re all dark brown. Impossible to tell.’

‘They’re murdering people?’

Collins laughed. ‘No need. The morgues are full of unclaimed bodies, there’s plenty of stock. The Thames is practically choking on headless corpses.’