‘That’s just it, Mr Holmes. She’s gone. Done a runner. Mr Lestrade thinks she’s the killer. Can you come, sir? Time is of the essence!’

Holmes turned to Polly, who was frozen in horror. ‘Polly, you must stay here for the night. Providing I can take care of pressing business here, either Watson or we both will return to Cambridge with you in the morning.’ He ran to the landing. ‘Mrs Hudson!’ he shouted. ‘We will have a guest.’

CHAPTER 25

The Cauldron of Death

We arrived at Wilton’s Music Hall to find the auditorium had been emptied except for one slender young lady sobbing in a corner, attended by a matronly figure I recognized as the ticket taker.

‘Annie! Oh, Annie!’ wailed the young woman.

At the end of the hall, a small crowd of police clustered onstage next to a large, strange copper vessel suspended by a thick chain and floating three feet above the raised floor of the stage. The thing, perhaps five feet in diameter, looked oddly like an ornate bathysphere, ready to transport an intrepid traveller to the dark ocean depths. It was only missing a porthole. A decorative stage sign prophetically named it ‘The Cauldron of Death’.

As we approached, I became aware of the terrible odour of burned flesh. There was another smell mixed along with it, some kind of chemical.

We mounted five steps to the stage and approached the vessel. It was decoratively covered in rivets and piping, with the occasional large crystal, making it look for all the world like a fanciful creation of Jules Verne. A three-foot square hatch opened to the front and was ajar, but only a crack. Another smaller hatch on top was wide open.

Dangling from both of these openings were a variety of ornate padlocks, all hanging open. A grate underneath the cauldron revealed still smouldering coals in a pit below the stage. A ladder with a platform on top stood next to the thing.

And next to this ladder was the first horror of the evening.

Lying on the stage was the body of a slender woman in a sparkling red dress. A cloth had been laid over her face and upper torso. I gasped.

I started towards the body, but a young policeman put a hand on my shoulder. He shook his head sadly. ‘Dead,’ he said.

If Madame Borelli was a suspect on the run, who was in her costume? ‘Who is it?’ I asked.

‘Name’s Annie Durgen. A girl they just hired today.’

‘Watson, examine the girl’s body, please,’ said Holmes, approaching the front hatch of the giant cauldron. He peeked inside and grimaced. I noticed his extreme reaction and he waved a finger at me, coughing at the fumes.