WRITER'S CUT / Steps to movie heaven: Christopher Hampton on transferring Sunset Boulevard from the screen to the stage

I WAS struck by the shot in Billy Wilder's Sunset Boulevard when the main character arrives at the house. There's a car chase, he pulls up the drive and his pursuers don't see him - their car goes by. Then he comes away from the garage and there's a strange diagonal staircase. He goes up it and the camera tracks up, a sort of crane shot. There's a bit of narration and music and you get your first sight of the house (it was also the house where Nicholas Ray shot Rebel without a Cause). It's very enigmatic, very weird, like a shot from Last Days at Marienbad. However many times you see it, Sunset Boulevard is still an extraordinary film - and an extraordinary film to have managed to get made then.

Originally, that moment of the arrival at the house wasn't staged in the musical, but I always thought that there should be a kind of breathing space, like going through the gate to the secret garden, before the story began. So I tried to find a theatrical equivalent to that shot, and to work out the constituents that work so well. In the film the outside staircase in the garden has a sort of affinity with the staircase that Norma Desmond comes down at the end, which we finally figured out in musical terms - we're using a piece of music there with a lyric that's a kind of mirror-image or an inversion of the lyric at the end.

We're not really going for pseudo-filmic devices; in fact we've rather avoided it. For example, in the scene where they're watching the silent movies, I wanted very much not to have a silent movie. So they sit on a sofa looking towards the audience and the movie is projected out in front of them; it's evoked with music. Really because the story is so character-based we use theatrical devices rather than cinematic ones.

Christopher Hampton wrote the book for the musical 'Sunset Boulevard'

(Photograph omitted)