Since he was sometimes required to enter a property illegally, he always carried a selection of skeleton keys with him. Taking them out, he got to work. It took almost ten painstaking minutes before he finally succeeded. He rifled quickly through the drawers but found nothing that really interested him. There was no money, no correspondence and no address book. The assassin was patient, knowing that desks of that kind often had hidden cavities in them. Searching for a spring, he explored each of the drawers in turn. At his third attempt, he heard a ping and a secret drawer suddenly appeared.

He had no time to count the wad of banknotes but estimated that he’d found several hundreds of pounds. It was the pile of correspondence that really interested him. Leafing through it, he came across a letter from Robert Vane, agreeing to be in St James’s Park as requested. But there was another name that he’d come for and he eventually found it. Written in a looping hand, it offered congratulations on the way that Sir Roger Mellanby had been killed, then ordered that the man responsible for his death should himself be murdered.

When he saw the signature on the letter, the assassin was baffled.

It was worthy of a celebration. Having demonstrated his skill at escape, Harry Scattergood took his friend to the nearest tavern and let Alan Kinnaird buy the drinks.

‘How did you do it, Harry?’ asked Kinnaird, raising his tankard.

‘It takes a lot of practice.’

‘And are you sure that I can learn everything necessary?’

‘Yes, I am. Then you’ll feel confident that you can walk out of anywhere they lock you up. Newgate is the most likely place.’

‘You went in one door and out through another.’

‘When I’ve wet my whistle, I’ll tell you exactly how I did it.’

‘And do you really think that we’ll get all that reward money?’

‘We won’t, Alan. It will belong to Giles Clearwater. He’s the one who’s going to get his hands on it.’

‘You promised to tell me why you chose that name.’

‘Yes,’ said Scattergood, ‘I did. Well, it was quite by accident, really. I was in a shop that sold maps, cartoons and old theatre posters …’

Yeomans glowered across the table at the Peacock.

‘Could you say that again?’ he asked.

‘He’s in The Provok’d Husband,’ said Ruddock, beaming.

‘And what, in the bowels of Christ, is that?’

‘It’s a famous play, Mr Yeomans. At least, the author thought it would be famous but it more or less died after its first performance. Mr Howlett explained that there’s a much better play, written well over a century ago. It was called The Provok’d Wife by Sir John Somebody and another playwright thought he could copy him. It’s in The Provok’d Husband that Giles Clearwater appears.’