Despite the reassurance and the weapon he carried, Henrietta was nervous. I could tell by the way she stretched out her slender arm as far as it would go rather than get too near. It was the way a child might approach a dog, scared it might turn vicious and bite at any moment. Up on the stage, Henrietta circled the Leopard Lady, each time getting a little closer. When she felt quite safe, she reached into her bag. She found what she wanted in a moment. From where I stood, I couldn’t make it out at first. Then I realised it was a pair of gloves. She drew them on one by one, slowly and carefully for the cream lace was delicate. Her hands protected, Henrietta extended a forefinger, and drew it down the Leopard Lady’s arm, from black to white to black again. It was what a painter might do to mix grey but the colours refused to bleed into one another. Puzzlement registered on her face and she tried again, rougher this time.

‘Is it a trick?’ Henrietta asked.

All the while the Leopard Lady stood motionless, her eyes averted from Henrietta, her face temporarily blank.

‘Rather noble, isn’t she?’ I heard a man in the row of seats ahead of me mutter, but all I could see in her was terror. The so-called Leopard Lady was bracing herself, but what did she think was coming? She might do all she could not to see what was happening, but I knew there was nothing she could do to stop feeling it.

One of the gentlemen rose from his seat. He was middle-aged and wiry; his lilac waistcoat hung loose like it had been made for someone else. I did not know him but I had seen him in the drawing room earlier in the evening. He climbed on to the stage and the Leopard Lady’s eyes grew wide as he loomed over her. Henrietta pulled a face as the man spat into his silk handkerchief. He wiped it across the Leopard Lady’s cheek as though her colour was dirt that could be lifted off. When this had no effect, he scratched at the black skin with a fingernail and the Leopard Lady flinched.

Crillick watched on, a half-smile on his lips. He gestured to the table of instruments.

‘Here I have lemon juice, soap, acid. None of these will remove the colour on the flesh, nor can it be scraped away with these.’ He held up the pincers. ‘Come, see for yourselves.’