I climbed out of the car, locked it, and walked up to the front step.

Inside I could hear a piano, a fractured chord being repeated again and again, muffled voices. I hesitated, just a moment, and then I pressed the doorbell, hearing the sudden answering stop to the music.

Footsteps in the corridor, and then the door opened. A forty-something man, lumberjack shirt, jeans and day-old stubble, stood there.

‘Yes?’

‘I wondered … is Lily here please?’

‘Lily?’

I smiled, held out a hand. ‘You are Martin Steele, yes?’

He studied me briefly before he answered. ‘I might be. And who are you?’

‘I’m a friend of Lily’s. I – I’ve been trying to get in contact with her and I understand that she might be staying here. Or that perhaps you might know where she is.’

He frowned. ‘Lily? Lily Miller?’

‘Well. Yes.’

He rubbed his hand against his jaw, and glanced behind him towards the hall. ‘Could you wait there a moment, please?’ He walked back down the corridor, and I heard him issuing instructions to whoever was at the piano. As he came back to me, a scale began playing, hesitantly and then with more emphasis.

Martin Steele half closed the door behind him. He dipped his head for a moment, as if he were trying to make sense of what I had asked him. ‘I’m sorry. I’m slightly at a loss here. You’re a friend of Lily Miller’s? And you’ve come here why?’

‘Because Lily said she came here to see you. You are – were – her stepfather?’

‘Not technically, but yes. A long time ago.’

‘And you’re a musician? You used to take her to nursery? But you’re still in contact. She told me how close you still were. How much it irritated her mother.’

Martin squinted at me. ‘Miss –’

‘Clark. Louisa Clark.’

‘Miss Clark. Louisa. I haven’t seen Lily Miller since she was five years old. Tanya thought it would be better for all of us when we split up if we broke off all contact.’

I stared at him. ‘So you’re saying she hasn’t been here?’

He thought for a moment. ‘She came once, a few years ago, but it wasn’t great timing. We’d just had a baby and I was trying to teach and, well, to be honest, I couldn’t work out what she really wanted from me.’

‘So you haven’t seen or spoken to her since then?’

‘Apart from that one very brief occasion, no. Is she okay? Is she in some kind of trouble?’

Inside, the piano kept playing – doh re mi fah soh lah ti doh. Doh ti lah soh fah mi re doh. Up and down.

I waved a hand, already backing away down the steps. ‘No. It’s fine. My mistake. I’m sorry to have bothered you.’

I spent another evening driving around London, ignoring my sister’s calls and the email from Richard Percival that was marked URGENT and PERSONAL. I drove until my eyes were reddened from the glare of lights and I realized I was now going to places I had already been, and I ran out of cash for petrol.

I drove home just after midnight, promising myself I would pick up my bank card, drink a cup of tea, rest my eyes for half an hour, then hit the road again. I took off my shoes and made some toast that I couldn’t eat. Instead I swallowed another two painkillers and lay back on the sofa, my mind racing. What was I missing? There must be some clue. My brain buzzed with exhaustion, my stomach now permanently knotted with anxiety. What streets had I missed? Was there a chance she had gone somewhere other than London?

There was no choice, I decided. We had to let the police know. It was better to be thought stupid and overly dramatic than to risk something actually happening to her. I lay back and closed my eyes for five minutes.

I was woken three hours later by the phone ringing. I lurched upright, temporarily unsure where I was. Then I stared at the flashing screen beside me, and fumbled it up to my ear. ‘Hello?’

‘We’ve got her.’

‘What?’

‘It’s Sam. We’ve got Lily. Can you come?’

In the evening crush that followed England losing a football match, the ill-temper and associated drink-related injuries, nobody had noticed the slight figure sleeping across two chairs in the corner, her hoodie pulled up high over her face. It was only when the triage nurse had gone person-to-person to ensure they were meeting waiting targets that someone shook the girl awake and she confessed reluctantly that she was just there because it was warm and dry and safe.

The nurse was questioning her when Sam, bringing in an old woman with breathing problems, caught sight of her at the desk. He had quietly instructed the nurses at the desk not to let her leave, and hurried out to call me before she could see him. He told me all this as we rushed into A and E. The waiting area had finally started to thin out, the fever-ridden children safely in cubicles with their parents, the drunks sent home to sleep it off. Only RTAs and stabbing victims, at this time of night.

‘They’ve given her some tea. She looks exhausted. I think she’s happy just to sit tight.’

I must have looked anxious at this point because he added, ‘It’s okay. They won’t let her leave.’

I half walked, half ran along the strip-lit corridor, Sam striding beside me. And there she was, looking somehow smaller than she had done, her hair pulled into a messy plait, a plastic cup held between her thin hands. A nurse sat beside her, working through a pile of folders, and when she saw me and registered Sam, she smiled warmly, and stood up to leave. Lily’s nails, I noticed, were black with grime.