I've missed my deadline for Twist. I told Tessa and my producer George Faber that I would 'easily' finish by the end of February.

I think I'm close but I had to do quite a bit of press last week which made it all a bit stop and start. It's really difficult not to say more or less the same thing when people ask the same kinds of questions, and I became more incoherent as the day went on. Then I had a great morning watching The Battle Of Algiers with a journalist for a speculative series. I didn't even know what a director did when I first watched it around 30 years ago, and was shocked to see how profoundly I have been influenced by it. The way I work and even actual images and sequences have turned up in different guises - images I had consciously forgotten...

"SKINNED ALIVE"

I went to Rome at the weekend (booked ages ago because I thought I'd be finished - ha, ha) and saw several versions of the Flaying of Marsyas - he was a centaur who got carried away by how great he was at playing music and challenged the god Apollo to a duel. He lost and was skinned alive for his presumption. Just now it all feels very close to home.

What I'm finding difficult is writing a genre script - a heist movie has its own rules which need respecting if not obeying. When the plot takes over too much, I lose the characters and it feels lifeless. When I let the characters off the leash, the script loses its shape.

Once I had the characters for The Principles Of Lust, they headed off. It had a pretty classic three act structure, though. In act one we meet Paul, who's completely stuck in his life. He has two dramatic encounters - he falls in love with Juliette, a lively single mother, and crashes into Billy, who's on a quest for endless thrills. In act two he's torn between these intense relationships. Then there's a denouement and a resolution, however weird in act three. I knew 'what it was about'. (Being constantly torn between wanting security and being terrified of boredom. Wanting excitement and not being able to bear the emptiness of just keeping wading further out.)

"FRENZIED BURSTS"

The Death Of Klinghoffer was also written in a series of frenzied bursts. I wrote it to the music, and once I had resolved the central problem of how to keep the story going during the choruses and how to integrate the historical narrative, it took on a life of its own. (I knew what it was about too. That some things are too terrible to forgive. But humanity is lost if we don't do it.)

I asked my son what he thought Twist was about. If anyone asked me I'd go on for hours about magicians and casinos and luck and grace and obsession. He replied. "It's about a boy and a girl who steal some money!"

The Principles Of Lust is being released this week. There has been some really good press but I know that some of the broadsheets are going to flay me alive.