The page. A predicament of Holmes’s own devising, then. A minute passed. It did not look like he was making headway. A bead of sweat ran down his forehead and into his eye. He shook it away. Smiled at me.

‘You won in Bath, then. A tidy sum,’ he said.

‘What? Oh, for heaven’s sake, Holmes.’

‘Tie pin. A handsome one from here. But it is not like you to purchase adornments.’

‘Stop this. No one likes to be scrutinized in this way.’

‘You are usually amused.’

‘Never mind! What the devil are you doing there?’

‘I am attempting to replicate The Great Borelli’s hanging escape trick. I have almost got it, I think.’

‘The Great Borelli?’

‘Travelling escape artist and magician. A wonder, at least in his own mind.’

Why Holmes felt the need to emulate some itinerant performer was a mystery. He flailed about a bit, and I could see that one arm had escaped its sleeve and was snaking underneath the canvas of the straitjacket. But the other remained pinioned.

A chair which had been placed underneath him had tipped over, and his legs now dangled limply in the air. I stood up, walked over and replaced it under his feet.

‘Don’t help me!’ he shouted. ‘I kicked it over for a reason.’

‘What reason?’

He did not answer but struggled a bit more. His pale face grew red with the exertion. Had this been staged for my benefit? Holmes did so enjoy an audience. But, of course, he had not known my return date from Bath, so … no. I moved the chair back away from him, then took a stack of papers piled on my usual armchair and dumped them on the floor. I espied today’s Times and freed it from the clutter.

On the way to my chair, I noticed on his chemistry table a black cylinder, perhaps eighteen inches long and six inches in circumference, mounted on a brass and wood device. Connected by cables were two small poles with a strangely shaped glass tube suspended between them. It had a somewhat malevolent look to it.

‘What the devil is this thing?’ I asked.

‘A Ruhmkorff coil,’ said he. ‘It’s a kind of induction coil. I can make tiny bursts of lightning at my desk. No, no, don’t touch! And a Geissler tube.’

I was sorry I had asked. It reminded me of the various quack devices I was constantly solicited to buy for my non-existent medical practice. It looked dangerous.

I sat and opened up the newspaper. After a few moments I glanced surreptitiously at Holmes, whose eyes were now closed in concentration. His struggles were painful to watch. I looked about the room and debated tidying it but decided the task was beyond my reach.