He almost smiled at this remark. 'You must allow me to preserve my secrets. But Mr Wilkinson knows what he is doing. He sent no proof of your identity because your very existence is its own proof.'

He stood up. 'Don't look so puzzled. It's of no significance. Have you done this before?'

I didn't understand a word he was talking about. All I knew was that even the dangers of walking alone across the Ile Saint-Louis would be preferable to staying in that dingy room a moment longer.

'I understand I am meant to collect a letter of some sort. If that is the case, please give it to me and I will be on my way.'

He snorted, as though I had just said the most imbecilic thing in the world, then reached under the mattress of his bed. As he did so, I noticed a pistol jutting out from under the dirty grey pillow.

'There you are,' he said. 'Take it and go. Deliver it to Mr Wilkinson as swiftly as possible. Do not stop, do not let it out of your possession for a second.'

He handed it over, and I looked at it. 'But it's not for him,' I protested. 'It is addressed to a Mr Robbins. I know of no such man.'

He stared at the ceiling, as though invoking the Lord to come and smite him.

'Yes,' he said heavily. 'How curious. However, fortunately your job is not to think but to move those little legs of yours in the right direction until you have accomplished your task. If I say it is to be handed to Mr Wilkinson, then to Mr Wilkinson it must go. Understand? Now go away.'

He turned, and lay down on the bed with a heavy sigh. The interview was at an end.

I glared at him with all the hauteur I could muster, turned and left.

My dignity was as offended by the encounter as was my sense of smell. I marched down the stairs, thankful only to be heading for the open air once more, my mind full of all the cutting remarks I might have made to put the appalling man in his place, and remind him that he was dealing with a gentleman. Not some servant, which I tried, unsuccessfully, to persuade myself was his own station in life.

I walked towards the river and safety, going more swiftly than usual because the sooner I was off that stinking island the happier I would be. My annoyance pushed all thought of danger out of my head as I walked, and my mood lightened with every step I took.

Apart from a heavy blow on the head and the sensation of falling forward onto the pavement – stone of some sort, I noted, with weeds growing up between the cracks, one with a bedraggled purple flower on it – that was the last thing I recalled for some time. It didn't even hurt, to begin with.

CHAPTER 2

When I woke up again I felt as though my head was splitting; stars danced in my eyes, and I could feel the blood pounding through my temples. I looked around as much as I dared, considering there seemed to be a real possibility that my head might come off entirely. Mainly I saw the ceiling – from which I deduced that I was no longer in the street, but had been picked up by someone and brought into a house. What was I doing there? What had I been doing? I groaned, tried to sit up, then collapsed back again. It was the smell that made me realise where I must be.

Then I remembered. The letter. My hand rushed to my pocket and felt for the reassuring crinkle of paper. Nothing. I tried another pocket, then another, then, just to make sure, went back and tried the first once more. Nothing. It had gone.

'Oh, my God,' I said as the realisation hit me. 'Oh, no.'

'Looking for this?'

I was lying on his bed, which smelled of dog and unwashed man. I turned my head, and saw the man I had met earlier, sitting calmly in a chair with the letter he had given me on his lap. The relief I felt was indescribable.

'Thank you, sir,' I said with genuine emotion. 'You rescued me from those scoundrels. Who attacked me? Did you see them? Who hit me?'

'I did,' he said, still calm as ever.

'What?'

He made no effort to help me out.

'Why did you hit me?'

'To steal this letter.'

'But you'd only just given it to me.'

'Well noted,' he said.

To be attacked in such a manner was bad enough; to be made fun of as well was well-nigh intolerable, and I decided that it was time to give this man a lesson he would not readily forget. I had spent much time at school in boxing, and felt that I could readily overcome the resistance of a man well past his prime. So I began to rise, but found that my legs were unwilling to support me; I waved my fists in his direction and even as he pushed me lazily back on to the bed with a contemptuous look on his face, I realised how utterly ridiculous I must appear.

I slumped back down, my head spinning, and groaned loudly.

'Head between your knees, until you stop feeling sick. I didn't break the skin, you're not bleeding.'

Then he waited patiently until I was once more able to lift my head up and look at him.