I suppose it's a sentimental thing, but I wouldn't want to do more 'Lewis' than we did 'Morse' because I do still think of it as an offshoot.

The ghost of Morse in the script was one of the things that attracted me to it.

I catch an old 'Morse' on ITV3. I've never thought I looked particularly like my son. He's taller than me and blond. But when I see Lewis walk into a room with John Thaw, it's like my son has just come onto the screen. That's very strange indeed!

I initially thought 'Lewis' was a terrible idea. The character had very much been Morse's work donkey and sounding board. But I was persuaded to do it, thinking if it was a flop, at least ITV would stop asking me. But the pilot took off, so we got back on this moving train, and we've never looked back.

Morse stared morosely at the blotting paper. "It's just not my sort of case, Lewis. I know it's not a very nice thing to say, but I just get on better when we've got a body - a body that died from unnatural causes. That's all I ask. And we haven't got a body.

People are very appreciative, and I'm always thrilled at how long the 'Morse' films have lasted. They seem to have an afterlife that goes on and on for decades, which is touching.