I looked at my watch. It was twenty past eleven. I don’t know how I’d managed to sleep in so late, but the pounding in my head told me that a mixture of whisky, vodka and Turkish wine had probably helped. The moment I padded out to the kitchen in my bare feet, I knew the flat was empty. Jill would have gone to work hours ago. Sure enough, there was a Post-it note from her stuck to the fridge. Quite a good review in The Times. Hope others are OK. Back at 6 p.m. Don’t forget laundry. Quite good. I knew Jill too well. We’d worked together for years in television and we both knew that ‘quite good’ was never good enough.

I wasted the rest of the morning. I was tempted to go out and get the newspapers or check them out online, but that’s something I never do any more. Why rush out in search of a self-inflicted wound? I imagined Ewan or Ahmet would call me with the bad news. It was always possible that Throsby had turned out to be the lone voice of dissent. Throsby and The Times. Maybe some of the other critics had loved the play. I decided that, for a few hours more, I would live in hope.

So I made myself breakfast. I had a bath and listened to music. I fiddled with the next book I was about to start writing – Moonflower Murders – but although I liked the idea of forward motion, moving on to the next project, anything that wasn’t a play, the words wouldn’t come. I stared out of the window at the Shard and St Paul’s Cathedral and vaguely wondered if it would be possible to hang-glide from one to the other. As it turned out, this was something Alex Rider would do in his next adventure. I drank two mugs of tea and ate too many chocolate digestive biscuits.

At ten past four, the doorbell rang.

I went to the intercom, assuming it would be a delivery. Living six floors up and with no video camera, I seldom saw anyone’s face. My day was punctuated by disembodied voices. ‘Yes?’

‘Mr Horowitz?’

‘Who is this?’

‘It’s the police. Can we come in?’

My first thought was that something had happened to Jill or to one of my sons. I hurried down six flights of stairs and over to the double set of doors at the end of the hallway. I was still in my bedroom slippers and I had forgotten my keys, so I had to wedge the inner door behind me with one foot whilst stretching awkwardly to push open the outer one. And that was how I was, strangely contorted, as I took in the two figures standing on the pavement and realised that I knew them and that they were really the last people in the world I wanted to see.

The bulky frame of Detective Inspector Cara Grunshaw was blocking my view of Cowcross Street with an expression on her face that brilliantly amalgamated a scowl and a smile. Her assistant, DC Mills, was behind her.