I did not steal from a dying man. He tricked me into going on that journey. He sweet-talked me into bed and promised me marriage when we reached our destination. Not that I believed the last part: I never pretended to be an innocent. But I didn't expect to be stranded alone in the middle of nowhere.

As for the map, he wanted to burn it. "It's brought death on me," he said. "I'll put an end to it before I'm gone." He was too weak to set light to it himself, so he told me to do it.

I tried. I pushed it into the fire but the flames never so much as charred the edges. And after he was dead, I needed to get back home. I didn't know where I was; I didn't speak the language. Why shouldn't I use his map to find my way if I could?

At first I couldn't make any sense of it. The lines seemed to shift around as I stared at them. The old man had pricked a finger every day to trace our route in blood. But by that showing, he had left me in a city, not a scrawny little village in the middle of a forest. I puzzled over the map until I saw something I recognised: the Lost Library, marked with a miniature of a many-windowed house. I used to love the tales of the Library I heard in my childhood. If you took them a book they didn't already own, you were allowed to stay for as many nights as there were pages in the book, with free board and lodging. The house was as grand as a castle but more comfortable and the company was better, my mother used to say.  I spent hours working out what book I could take to earn a stay there. Would my diary count? Or the local guide to our town? The Library had become lost, years before I was born, so I never expected a chance to find out.

Now I had a route to follow, although I didn't have anything to contribute but the map itself. That folded into a dozen pages or more: the number changed every time I counted. Even if I was only allowed to stay a few days, I would see the place and find out where to go next.

How was I to know the map can't be copied or studied? I had a struggle to get to the Library but it all seemed worthwhile. I feasted in the Great Hall the night I arrived and slept in a feather bed for the first time in months. The next day, they were furious with me for making fools of them. They made me tell them how I'd come by the map and then they locked me up. They can't afford a reputation as receivers of stolen goods, they said. But I never meant to steal. Can't you help me get out of here?