Buttons sobbed, burying his face in his arms. ‘If only …’ he wailed.

‘Find him dry clothes, and make sure he stays warm,’ I said and left as the young policeman helped Buttons to drink. Perhaps Lamb could offer some comfort or even some insight. As I left the cell I glanced back at the young deacon. It struck me that saving a man for the second time in a day only to send him to the gallows was a questionable act of mercy.

Back in the hallway, a red-haired constable I had glimpsed at the riverside hurried by me in the hall.

‘Excuse me, Constable!’ I called out. ‘Father Lamb, the Catholic priest who was at the reception desk? He was called to see this prisoner. Do you know where he is?’

The man shrugged. ‘He wasn’t called for Buttons. It was for that other young man from last night.’

‘One of your drunks in there?’

‘Oh, no. Tall, pale fellow. Vittle or something, I think. Odd character.’

‘Leo Vitale?’

‘That’s the one. Wanted to make confession.’

How strange. But Leo Vitale was an Italian name – perhaps he was Catholic. Did asking to confess imply guilt? Holmes had said something about Vitale possibly being a third man in Buttons’ room at the rectory the night of the murder. And now Vitale wanted to confess.

This was news Holmes needed to hear.

‘Where is Vitale?’ I asked.

‘Out back, I think. We have an extra cell in what used to be the stables. Five prisoners last night. That’s crowded for us,’ he said with a laugh, then departed.

I ran back to Holmes’s cell in the desperate hope that he was still in the building. I was in luck. He had escaped his bonds and the cell itself but was still in the small anteroom where, as yet, no one had spotted him. There he had lingered and was leaning, rather casually, I thought, against the wall.

He glanced up. ‘Buttons is all right?’ His voice was weak.

‘Yes. Mild shock, but he is being treated. Give me my knife back,’ I snapped. Holmes reached into his pocket shakily. His face was ghastly white. ‘What is the matter with you?’ And then I saw it. ‘Holmes, your shoulder! You dislocated it again, you damned fool!’

‘Pop it in for me, Watson, that’s a good fellow,’ he said, handing me back my knife.

I could not take my eyes off him and fumbled as I put the thing in my pocket.

‘Now, if you don’t mind,’ he said.

He was right. I needed to work quickly before swelling made it impossible. There was no time to bring him to task for this foolish manoeuvre.

‘Stand away from the wall,’ I ordered. ‘Hold onto these bars with your other hand, and brace against me.’ I felt the injured shoulder. ‘Dear God! Why didn’t you wait? Hadley will release you eventually.’

‘Watson. Do it now!’

‘Steady, there.’