I had a plan to write a book about Charlie, Daniel Owen’s frequent sidekick and friend. I started the book, and I have a clear story that I want to tell. I have the book cover (which is gorgeous). But then Paul Qayf got in the way, and insisted that I told his story first. Now I know and you know that these people aren’t real, but Paul didn’t get the email, and kept banging away until I agreed. That meant another book set in Kent, though a different area this time.

I used to live in South London, and Kent was the nearest area of wild country, so I spent a lot of time exploring. Even after I moved to Wales I visited regularly, including spending time in the Medway area. I’ve messed around with the geography to obscure where the events in the book take place. If Dickens can do it, so can I. Ledmarsh does not exist, except in my imagination. But the river and the forts are real (although the fort at Ledmarsh is a mash-up of several real forts).

Forts of all ages cover the Medway–and the whole coast of Britain, and the more I researched them, the more obsessed I became. Many of the forts have simply been abandoned to the urban explorers and the sea birds. Some have been turned into houses, holiday destinations, or museums. At the time of writing there is one for sale off the south Hampshire coast for £3million–and you need a helicopter to get there. Great views though.

The forts built to repel Napoleon’s ships are the model for the fort at Ledmarsh. They were built (with obvious care, and lovely details) and then hardly used.

The forts in my picture were used, not just in war, but also by pirate radio stations. I think they look like alien invaders, and I can’t imagine how frightening t must have been to have served in one, high up above the waves, with only the spindly legs to keep you safe. By contrast the Napoleon-era forts like my imaginary Ledmarsh fort, were massive and heavy, built on solid ground.

I did most of the research for this book online, but I have a firm plan to go fort-visiting next year. But first I have Charlie’s book to finish.