Screenwriter Jack Thorne on the gruelling, glorious business of adapting His Dark Materials for television

Writing adaptations is a process of gaining true understanding and then using it. You have to see the soul of the books you are adapting in order to preserve it. That is your job.

I’ve spent much of my professional life on adaptations. Some have made it to screen or stage – among them, Harry Potter and the Cursed Child; Dickens’s A Christmas Carol for the Old Vic; and the film of RJ Palacio’s Wonder.

In my twenties, I’d devoured Philip Pullman’s His Dark Materials. I’d bought the novels for my mum, and read them again, and discussed them with her. Yet the idea of adapting them for the screen – three huge books filled with glory – was terrifying. They are great literature. In fact, they are a masterpiece. It wasn’t enough to have read them. I knew I needed to do a PhD in them.

That meant writing papers on Dust, understanding the metals involved in subtle knives, trying to grasp the incredible science behind His Dark Materials. It meant, with my script editor Xandria Horton, plotting journeys, making maps, defining the way that certain characters get from A to B.