Without preamble, he launched into an inspection of the outside of the cauldron by running his hand over its surface. His face was grim, but I sensed the humming excitement beneath. Near to him stood the stolid figure of Falco Fricano, Borelli’s brother-in-law.

I turned my attention to the corpse, and a stagehand quickly informed me of the means of death. The poor young woman had been up on the ladder and leaning over the cauldron, conversing through the top opening with Borelli, supposedly trapped inside – all part of the planned act.

But an unexpected explosion blew up in her face, and she fell backwards off the ladder to the stage below. My examination confirmed third-degree burns on her face and hands. However, the broken neck from her fall was the apparent cause of death.

I looked up to see Holmes in conversation with Falco Fricano just a few feet away. The muscular Italian stood woodenly, his face pinched in what might be grief, a reaction to the gruesome events. His fists were clenched, and he leaned strangely backwards on his heels, which rather than making him look frightened gave the impression that he was gathering himself to launch at Holmes or to flee. He struck me as someone holding himself back at great cost.

‘Mr Fricano, you hired Miss Durgen just today to go on in place of Madame Borelli?’ asked Holmes.

‘Yes.’

‘And why is that?’

‘Madame refused to perform.’

‘Did she give her reason?’

‘The Great Borelli and she had a big argument, I do not know about what. The hotel said there was much shouting.’

‘Where is Madame now?’ asked Holmes, looking about the stage.

‘No one knows. Mr Borelli told me they were finished.’

‘Mr Lestrade is at their hotel room now,’ said Hamilton as I approached.

I glanced over at the front hatch of the cauldron. I knew I should lean in and take a look, but I hesitated. In due time, I would. I joined Holmes and Hamilton.

‘I see,’ continued Holmes. ‘Describe this act in detail. I need to know precisely what happened. Tell me exactly what the audience saw, and how it works.’

Fricano cleared his throat. He began with great effort. ‘First, the Great Borelli, he comes onstage.’

‘In a wheelchair tonight, I presume. Watson set his broken ankle recently.’

‘No. With a walking stick only. The Great Borelli, he is very strong. He removes the cape. Then the young lady, she spins cauldron to show no door in back.’

‘Like this?’ asked Holmes. He placed one hand on the cauldron and gave it a shove. The thing was set to rotate on the chain hanging from the rafters above the stage, twirling easily so that now the back faced us. Holmes stopped its movement with a hand. ‘Except for this well-disguised hatch, here?’

‘Yes.’