I stood in front of the police station, at a loss. It was midday, and the sun was high in the sky, the heat shimmering through the air causing the edges of the building to waver in front of the eyes. Or perhaps it wasn’t the heat …

I mopped my forehead with my handkerchief. I felt faint. I had eaten nothing since dinner yesterday. I didn’t know how Holmes managed to go without food. It was as though a fever of energy overtook him while on a case.

But what to do? My friend was more confident of his release from gaol than I was. At a nearby post office, I wired Mycroft Holmes, informing him in the briefest terms of his brother’s circumstance. What happened next, while deeply disturbing, nevertheless proved to be providential in this case, in which so much went so terribly wrong.

I decided to return to Dillie’s hiding place in the diminishing hope that at least Polly might have returned there in our absence.

I walked down St Andrews Street and came upon a forlorn two-storey brick building with bars along the upper windows. As I passed, I heard a female scream emanate from a window above me. ‘Noooo!’ came the anguished cry, followed by a shriek of pain.

I hesitated. The cry came again and turned into a wail. Someone was suffering agony in that building. Without a pause, I raced through the front door. It was some sort of public place, and a sharp-faced man sat at a reception desk and looked up at me with a face compressed into a permanent scowl. ‘What do you want?’ he said.

‘I – I heard a cry!’ I said. ‘A woman. It sounded like she was in pain.’

‘Sir, you have no business here.’

‘I am a doctor. If someone is in such pain, perhaps I can be of help.’

‘Be gone! It is not your affair.’

‘What is this place?’

‘It is the Spinning House.’

The Spinning House! This was the place Holmes had mentioned where women were held without trial by the special University police – outside the regular law.

‘But what is happening upstairs?’

Abruptly the wiry gatekeeper stood, picked up a walking stick and came round from his desk. He held the stick in a way that said he might make creative use of it. ‘Now, be gone!’ he growled.

‘As a member of the public, I demand to know what is going on here,’ said I, placing my own stick in front of me. I would not be intimidated by this toad.

‘Don’t you know what this place is?’

‘Yes! I have heard that you people arrest women who seem to be consorting with students and hold them here without trial.’

‘Trial!’ he spat.

‘Do you torture them as well? I will call the real police if you do not explain to me what I just heard.’