Holmes looked up, scooped up his watch and crossed over to Polly. I followed. She pointed to a locked case in which were a wide variety of jewelled rings. ‘Those two,’ said she. ‘The big diamond one, there, with the two emeralds – that’s from Mr Eden-Summers. And the littler one with the sapphire is Mr Vitale’s.’

‘You’re sure, Polly?’ asked Holmes.

‘As sure as this lady thinks we’re about to steal ’em.’

Indeed, the woman now held her stick aloft and ready to strike, and her husband appeared behind her, now pointing a gun at the three of us.

‘Hold your stick, please, madam. And sir, be assured,’ said Holmes, ‘we mean you no harm.’ Holmes raised his hands and nodded to Polly and me. We followed suit. The woman lowered her stick, but her husband kept his gun trained on us, or rather on Holmes specifically.

‘This is as I thought,’ said my friend. ‘Dillie had planned this all along, to fund her escape. May I see these two rings please, sir?’ asked Holmes. He began slowly to lower his hands.

The pawnbroker hesitated but did not lower his gun. ‘You buying or you selling?’

‘I am buying,’ said Holmes, clipping his watch back onto its chain and replacing it in his pocket.

‘Vat is this all about?’

‘I would like to purchase information from you, sir. There is a young woman who I believe has been bringing in items, including these, to your shop. I would estimate she has been doing this over the last year.’

‘Year and a half, more like,’ said Polly.

‘I wish you had mentioned this before,’ said Holmes.

‘She weren’t dead before.’

‘Dead?’ exclaimed Mrs Flan. ‘Piotr! This is a police matter!’ She raised her stick menacingly. ‘You three! Out!’

‘Calm yourself, Luisa! People die. That’s life.’

A philosopher! I suppressed a grin, catching Holmes’s sidelong glance at me.

The man turned to Holmes. ‘I don’t gossip about my customers,’ rasped the old man. ‘Otherwise I vould have no customers.’

‘Understood,’ said Holmes. ‘But I am prepared to buy this information from you. There is no threat implied, you obviously run an honest business. Here is a picture of the young lady.’ From his pocket he removed a daguerreotype of Odelia Wyndham.

‘Where did you get that?’ I asked, surprised.

‘Freddie was kind enough to lend it to me,’ he said. ‘Without his knowledge.’ A little smile.

The old man eyed the picture. ‘I am not sure. I may have seen her. May have not.’

There was a long pause.

Holmes took out two sovereigns and laid them on the counter. The man pushed them back towards Holmes.

‘No. I am still not sure.’

Holmes frowned. ‘Watson?’

I reached into my pocket. I found a five-pound note I was carrying and reluctantly added it to Holmes’s coins on the counter. The man’s face melted into what passed for a smile.