It was an evening in October a year later and it had been a long and tiring day: I’d slept badly the night before and Toby had been difficult for most of the afternoon – he was two years old by then. I’d promised myself I wouldn’t have a drink until both of the children were in bed so I was doing my best to chivvy Hannah along. Toby should have been in bed ages ago but he was refusing to settle, so I’d brought him into the bathroom with me while I kept an eye on his sister.

‘Come on now, Hannah,’ I said for what felt like the hundredth time, while Toby played on the floor, making a relentless ‘brrrrmmm brrrrmmm brrrrmmm’ noise as he pushed a toy car around my feet. ‘Get out of the bath now – it’s getting late.’

She glanced at me dismissively. ‘No, I’m not ready to.’

My anger seemed to come from nowhere. I was usually so careful to keep her onside, but I was tired, a bit hung-over from the night before, and there was something in the look she shot me, the disdain in her eyes that just made me snap. ‘Get out of the bath right this minute,’ I shouted so loudly that Toby jumped and started to cry. ‘I’m sick of you disobeying me!’

With infinite slowness, a maddening smirk on her face, she did what she was told. It seemed to take her forever, and I was suddenly desperate for a drink. I passed her a towel. ‘Go and put your night things on,’ I muttered. ‘I’ll be two minutes.’ I left the room and headed for the stairs, thinking only of the cold bottle of wine I had waiting for me in the fridge.

After I’d poured myself a glass I stood at the sink savouring that first gulp. I could hear Hannah talking to Toby, their voices getting louder, which meant they must have left the bathroom. I closed my eyes, summoning my last scrap of energy, then knocked back the rest of the glass. That was when I heard the scream. I ran from the kitchen, the bottle still in my hand, to find Toby lying at the bottom of the stairs. I heard myself shouting his name as I knelt down beside him. Time seemed to stop: I was senseless with panic. The relief I felt when he got up and threw himself into my arms was indescribable. ‘Are you OK?’ I asked as he screamed hysterically. ‘Oh my darling, are you OK?’ Frantically I checked him over for broken bones, but miraculously he seemed unharmed.

I have never known fury like it. When I looked up, I saw Hannah sauntering down the stairs towards me, a serene smile on her face. I admit, in that one brief moment I wanted to kill her. ‘What did you do?’ I screamed. ‘What the hell did you do?’