He turns and shows me his right hand. There’s a crescent-shaped scar running from the knuckle of his thumb to the wrist.

‘My father heard the noise and told the kids the party was over,’ he spits out bitterly, returning to the window. ‘When they had left I went to look for him. The house was deathly quiet but the garden door was open. Outside, the torches were still lit, the stalls still up and the cushions still strewn about the lawn. And then I saw him, sitting with his back to me, huddled in the light of one of the torches. He looked up and, when he saw me, his face grew dark. He ordered me to explain my behaviour, why I had thought it necessary to smash the window and cause a scene. I pleaded with him, explained that I’d just got fed up with the noise, that the broken window had been an accident. But that wasn’t good enough for my father, nothing ever was.’

I sit here trying to reconcile the jovial Geoffrey, chat-show favourite and children’s hero, with the person his son is describing.

‘He told me that I shouldn’t have been in my bedroom,’ he continues. ‘That my job was to stay at the party and play the role of Angus. But I was sick of having to pretend. I wasn’t bloody Angus. He got angry then and told me to mind my language. And then I really lost it. I told him how ludicrous it was to hear that from the man who valued all my thoughts, all my experiences, enough to trap them inside a story, but in real life couldn’t stand me. Who wouldn’t come near me no matter if I yelled or cried. And yet he felt the real crime was a bit of bad language. He screamed back that I ought to be honoured to be his muse, that most boys would be thrilled to be the subject of a bestselling book series.’

He shakes his head and pauses. When he resumes the story his voice cracks with emotion.

‘I … I told him I didn’t want to be his muse, I wanted to be his son. And you know what he said? He said that whether I liked it or not, I was his son, and a spoilt son at that. That he had given me everything I could have ever wanted: a beautiful home, money, holidays, more than most boys would have in a lifetime. But that wasn’t what I wanted, that wasn’t what she wanted, my mum. All she wanted was to stay in our tiny house in Mallison Street where he had written the first book, which sold so well he could afford to buy this place. Mum hated it here. Neither of us wanted what he gave us. And you know what he said then?’