I called the boy over to ask what time it was. Half past five. Lucien would be well on his way by now, but I couldn’t wait here any longer. I hurried out of Hussmann’s, walked up towards the main road, and dimly heard a coachman swear as I crossed over Oxford Street without checking for carriages.

Amid the chaos in my head, as I tried to think how I could save her and the boy as swiftly as possible, I didn’t hear Lucien call my name, but I did feel it when he grabbed me before I stumbled into the path of yet another carriage. For a moment I collapsed into his arms, flooded with relief.

‘The Odditorium,’ I stammered. ‘We have to get there. Now.’

‘Zillah, what has happened?’ Lucien said.

I was looking up and down the street for a cab and he trailed after me.

‘She’s at Northumberland Avenue,’ I said.

But he looked at me blankly. He didn’t understand the significance of that address. Nor could I tell him too much without the risk of revealing my relationship with Vincent.

‘I wasn’t expecting somewhere so close to the theatre,’ I said lamely.

‘It is not far from my shop. But, Zillah, you can’t think of going there now. It will not be a matter of bursting in and taking her. You said there are others to think of too?’

He was right. I’d gone off at half-cock when I went down to the docks. It hadn’t mattered. The Leopard Lady was long gone by the time I discovered where Crillick had first held her, but this time I could not afford to make the same mistake. It meant leaving her at the Odditorium for another day, when even an hour was too much, but I had to make sure everything was in place.

‘Black Bill’s information was that she’s paraded before an audience twice a day. Once in the afternoon and then again late evening. Our best chance will be between her performances.’

If the matinee show started around three o’clock and lasted an hour or two, and the evening show was at ten o’clock, that gave us a clear window to get her out, and all the others too. God knows what state they were kept in. We’d need a carriage to get them to safety – maybe more than one.

‘Shall we think of a plan together?’ Lucien said.

Now that I’d had a minute to calm down, I could see the sense in working out the best way to free the prisoners. It had been a shock to find out where the Odditorium was, but I could use my knowledge of 25 Northumberland Avenue to my advantage. Grace and I had always got on well. Could I count on her to help me?

‘We could go there tonight to see it for ourselves,’ Lucien said.