I could hardly bear to ask. I had no idea how old the Leopard Lady’s son was, but the thought of what they might be doing to him was monstrous. I’d seen the scientific papers that Crillick had left around the house. There was a theory they could tell intelligence from the shape of a person’s skull, but knowing Crillick’s cruelty, head measurements were likely the least of it.

‘I don’t know about that. But this Leopard Lady is not alone. Her name was only one on a list of several.’

‘Can you tell me exactly how many?’

These nameless others had been worrying me more and more. I might not have seen them but their plight was every bit as bad as the Leopard Lady’s. For all I knew, they might be in an even worse state.

While Bill threw back his boiled water, I unfolded the paper he’d given me. It was the very piece that he’d written the words ‘The Odditorium’ on last night, but now two more lines – an address – had been added beneath.

Bill was getting to his feet but stopped when he heard my gasp.

‘Wait. This can’t be right.’ There’d been some kind of mistake.

The other patrons looked up at the sound of my raised voice. Black Bill sat down again, with a stern look. He did not appreciate anyone making a scene.

‘Don’t call me a liar, girl. My man was there not two hours ago, watching the house. I’d say the show is in the cellar.’

‘Twenty-five Northumberland Avenue?’ I said it in a half-whisper.

‘That’s right,’ he said.

‘Vincent lives there.’

‘You can’t trust them, Zillah,’ Bill said, not unkindly, and I wasn’t sure if he meant the English or the quality or both.

He leant back from the table, watching me coolly as I struggled to make sense of what I’d learnt. I’d always prided myself on keeping my wits about me, but I’d let myself become so wrapped up in being an exotic princess in the eyes of a viscount, I’d failed to notice that, two floors below in the basement, the Leopard Lady, her child and others like them were being exhibited and experimented on in the name of entertainment.

It was a fresh bowl of coffee that brought me back to myself. Bill had left, but I still held the note in my hand. I could scrunch it up, burn it, but that wouldn’t erase the truth. The banging, the crashing at Crillick’s house. That’s what it had all been about. I’d gone searching for the Odditorium downriver but all the time it was being built right under my nose.