I never set out to write more than one Varjak Paw book. I started with the story of a kitten coming into his power, growing into a cat – and for me, that story ends at the end of Varjak Paw.

But writing it, I’d found all sorts of questions that I couldn’t answer in one book. Take Sally Bones, boss of the meanest gang of streets cats in town. Varjak had made a terrible enemy there; what was going to happen when he went back to the city? It was clear that I was going to have to write a sequel.

But I don’t usually like sequels. As a reader, there’s nothing I hate more than a sequel that lets me down, and so many of them do. There was no way I could let that happen with Varjak. I promised myself there would only be a sequel if it was as good as the first one, if not better. It needed to be a great book in its own right, with a story that could stand alone and take us somewhere new.

I didn’t think it would be all that hard; I already had characters, situations, places… how hard could it be? Well, it took me three years and 11 drafts, and I can honestly say it’s the hardest thing I’ve ever done! Here was my problem. In the first book, a powerless kitten becomes a powerful cat. That’s an interesting story. But a character with power is just not that interesting. He can fight his way out of any corner, so where’s the story?

I tried all kinds of things. I explored the city, and found whole new areas. I discovered some great new characters, like the Scratch Sisters, the Orrible Twins, and of course Buster and Bomballooloo, who I think have the best names in the book! But Varjak’s underlying story just wasn’t there. Nothing felt as exciting as what had happened in Varjak Paw.

Around draft eight, I remember feeling totally lost. I felt sure I’d never complete the book. I thought I was finished as a writer. The first book was just a lucky accident, but now the truth was clear: I would never write anything else again. I wanted to give up. These were very dark times indeed.

But somehow… those feelings gave me the key to the story. What if Varjak felt exactly like I did? What if he believed he’d lost his power? How would he survive without all the skills he’d learned in the first book? What would he fall back on then? The moment I had that thought, the book came to life. The story came into focus, sharp and clear. It didn’t take long from there to finish it.

The Outlaw Varjak Paw went on to win the Blue Peter Book Of The Year – one of the most amazing things that has happened to me. But the experience taught me a very big lesson. You should only write a book if you already have a story for it. Otherwise, you’ll get as lost and confused as I did. So to answer a question that I’m often asked: yes, there will be a third Varjak Paw book one day – but only when I know what the story is!

SF Said is the author of Varjak Paw (winner of the Nestlé Smarties Book Prize), and The Outlaw Varjak Paw (winner of the Blue Peter Book Of The Year). He has just completed a new novel for DFB, an epic space adventure called PHOENIX, which will be published in 2013. He lives and works in London, but you can read a CBBC Newsround interview with him here, and click here to read an extract from Varjak Paw.
