Watchmen co-creator Alan Moore has been characteristically tight-lipped about HBO's long-awaited – and long-dreaded – update of his landmark graphic novel. But in this 2007 interview from the Telegraph archives, he sat down with Jonathan Strange and Mr Norrell author Susanna Clarke for an expansive, eye-opening talk about erotica, magic, and his East Midlands hometown

I first became an Alan Moore fan in Covent Garden on a Saturday afternoon in 1987, when I bought a copy of Watchmen, his graphic novel about ageing superheroes and nuclear apocalypse. I had always been fascinated by comics but it had taken me several weeks to make up my mind to buy Watchmen; for someone on a publisher's assistant's salary it was some quite unheard-of sum of money. I began reading on the Tube home.

I read all weekend and by Monday morning I still had a couple of chapters to go. For the book itself, I refer you to pretty much any review – intelligent, multi-layered, extraordinary, etc – but what I remember 20 years later is not so much what I thought of it, as its effect on me. That Monday at work I felt almost physically sick: sick from not being able to read Watchmen. The primary colours of Dave Gibbons's art danced in my head – everything else seemed grey and unreal. No other book ever took hold of me like that. That evening I went home and finished it. Then I was no longer sick. Only bereft.