Bill looked down at the green carpet. Muffled sounds of college life came in from the quad, and the window cast diamonds of sunlight at our feet. ‘We were away for hours, Al.’

‘Oh, it wasn’t that long.’

‘We left at four. I heard the bells go.’

‘That can’t be right. I looked at the clock in the lodge when we passed.’

‘Sure you did, Ali.’ His voice was bitter. I actually stepped back.

‘What should I do? They’re our friends. I don’t want to get them in trouble. Not when it’s some stranger, some townie who’s got in and . . .’

‘She’s dead, Al. Don’t you think she deserves us telling the truth?’

‘It is the truth. I don’t know what time it was when we left, but I know it was late.’

He stared at me. ‘You don’t have to do this. I’ll help you. I know you’re scared about what’s next, about him, but – you don’t need to be.’

A long moment ticked by. I stared down at the carpet. It did occur to me to wonder why I was doing this for Mike, when all he did was mess me about. But I’d tried for so many years to make him want me, never having any leverage, never any influence over my own relationship. Now that I had some, it was impossible to let it go. ‘I don’t know what you mean.’

Bill sighed. ‘OK, Ali. You do what you have to.’

‘Wait! What did you tell them? The police?’

Bill was already moving away down the stairs, his face in shadow. ‘Don’t worry, Ali. I didn’t say anything you can’t contradict.’ I hated the way his voice sounded.

He walked down the stairs again before I could say anything else, and I heard later on he’d left, catching the coach to Harwich and then a ferry out of the country, and I didn’t see Bill again until Jodi and Callum’s wedding. It was the last time until the night Karen was attacked.

‘Do come in.’ The police seemed kind. There was a younger woman with chestnut hair pulled back, and an older man who was grey-haired and paternal. Deliberate, maybe. A lot of us would be wishing our dads were on hand to sort things. Not me, of course.

I sat down, tucking my feet nervously under the wooden chair, feeling like it was a tutorial I hadn’t done the reading for. They consulted their notes. ‘Alison, I understand you left college at some point before the breakfast, when we discovered Martha.’

It wasn’t Martha any more, I told myself. She was gone, and nothing would bring her back. ‘Just for a walk. With Bill. My friend. The one who was . . .’

‘With Bilal Anwar.’