A siren wails in the distance, and I look up, my stomach flipping. Above the roofs, over in the direction of the Common, a halo of blue lights pulses a grim rhythm. I go back inside, quietly close the door, pick up the phone and take it back upstairs to Anna’s bedroom. From her window, I can see the lights better. It’s definitely the Common. There are problems there from time to time, especially with underage drinkers – groups of teenagers buying booze from the minimart and gathering in the gloom. I tend not to walk Toffee there at night if Nick isn’t around. Once someone was stabbed in the playground. It could be anything. I’m sure this has nothing to do with Anna.

‘I want to report someone missing,’ I say into the phone, my eyes fixed on the lights, and it all starts again.

‘What is your relationship?’

‘She’s a friend.’

‘Does she have health issues?’

The voice could belong to the same female operator. I wait for her to comment on this, to mention the remarkable coincidence of me calling to report a missing person twice in three weeks, to make some light remark about lightning not striking the same place twice, but she doesn’t, and maybe she’s not the same person anyway.

I know what the routine is, that she’s about to tell me to wait until tomorrow. I turn away, and sit down on the end of Anna’s bed, exhausted.

‘I’m really concerned about her,’ I say. ‘She’s left her child—’

There’s a noise, a quiet shuffle, and I turn to find Kai standing in the doorway, his eyes huge. I go to him, put my hand on his shoulder and lead him gently back to his bedroom. He climbs obediently back into bed, but I can tell he’s hyper alert.

‘How old is the child?’ the woman is asking.

The doorbell rings and I sag with relief. Anna must have forgotten her keys. Maybe she’s drunk.

‘It’s OK,’ I say. ‘She’s back. Sorry to waste your time.’

Kai springs up, but I block him. I want to check what kind of state his mother is in before he sees her. He struggles in my arms.

‘I want to see Mummy.’

The doorbell rings again, more insistently this time. I’m torn, but in the end I insist. It’s the right thing to do.

‘She’ll be cross if she finds you up,’ I say urgently. ‘And I’ll get into trouble.’ He looks at me and I can feel him wavering. He’s utterly exhausted, poor child. ‘Shut your eyes and count backwards from a hundred.’ It sometimes works with Lottie.