Kai looks from me to the inspector. ‘Why is he here?’

‘I called him because I was getting a little bit worried. Are you hungry, sweetheart?’ It’s barely four o’clock, but I don’t think there’s any point forcing him back to bed when he’ll just lie awake worrying.

Kai nods.

‘What do you usually eat for breakfast?’

‘Porridge. But Mum makes it.’

‘I can make it for you.’

‘S’all right.’

He goes to the cupboard and pulls out a box of cereal, the fruit and fibre kind, finds a clean bowl and brings them to the table. Marsh signals me to follow him out of the room and closes the door.

‘We’ll be in touch as soon as we know anything. Can you look after Kai until her family comes to get him?’

‘He’s never met them.’

Marsh raises his eyebrows.

‘It’s his dad’s parents he’s close to. I’m sure Kai will have their number on his phone. I’ll call them for you if you like.’

Oh shit, I think as I see the two of them out. I’ve been through this with Lottie, so I know what will happen. No answer will satisfy Kai’s craving. He wants his mum like Lottie wanted Nick, and when he twigs she’s not coming home he’s going to want to know why.

By this time a faint milky dawn is filtering into the house. I go back into the kitchen where Kai is sitting with his bowl of cereal untouched. I persuade him to brush his teeth and pack a few things, then I take him home. I let Toffee out into the garden and Kai goes out after him, but instead of throwing the chewed-up ball that Toffee offers him, his tail wagging, he stands there, staring at the houses behind, his shoulders slumped and his hands stuffed into his pockets. He comes back inside, I put the television on in the front room and he’s asleep on the sofa within seconds. At six, I phone his grandparents and speak to a sleepy Paula Foreman, Anna’s mother-in-law. She immediately says they’ll get a train to London and meet me and Kai at the hospital later today. She sounds a practical sort of person.

At nine Tim comes downstairs, freshly shaved, dressed in chinos and a pale-pink shirt. ‘I thought I’d go to the RA,’ he says. ‘Get some culture.’ He spots Kai and raises his eyebrows. ‘I got your note. What happened?’

‘This is Kai, Tim. Anna’s son.’ Kai is petting Toffee now, so I lead Tim out of earshot. ‘Anna was attacked last night.’

I watch him closely, but nothing in his reaction is abnormal, just surprise, shock, compassion.

‘Oh. I am sorry. That’s terrible. Poor Anna.’

‘Who was your text from?’

He looks at me innocently. ‘What text?’