I’m so incredulous, I laugh. ‘Even if that were the case, which it’s not, there’s no way of getting to that stretch of the river in a car. I’d have had to have carried him a quarter of a mile down a rough footpath.’

‘But, if Nick knew where Izzy went in, if that place meant so much to him that he chose to die where she did, then why did he leave the bag fifteen yards downriver? It doesn’t feel right.’

‘No,’ I agree. ‘It doesn’t.’

‘If he didn’t drive himself there, then someone else did. You didn’t know exactly where Izzy went into the water, did you?’

‘No, but I didn’t know Izzy Wells existed until a couple of weeks ago.’

‘So you say. You agree that, in the dark, it would be easy to mistake the footpath and leave the bag in the wrong place.’

‘I think we’ve heard enough of this,’ Harriet says impatiently. ‘My client maintains that she did not drive her partner’s body to the river. Once you’ve had Forensics examine the car I’m sure you’ll be able to prove either case to everyone’s satisfaction. But until then, perhaps we can move on?’

‘One moment.’ He holds his hand up. ‘There is the small matter of the missing wheelbarrow.’

I lean back in my chair and wait.

‘It was found in the woods. It’s being tested for traces of your and Nick’s DNA. If we find it, we will take that as confirmation that Nick was murdered. And don’t worry, we will find his body, Grace. It’s only a matter of time. Devon and Cornwall have a team working on it right now.’

I remember something. I see Anna striding away from me, and Mrs Burrows preventing me from following her. ‘Anna took off in a huff in the direction of the river. If she had expected to see the bag, and hadn’t, perhaps she’d been waiting for an opportunity to check without me there. Her temper tantrum did seem a little contrived. But she didn’t make it further than the lawn because a police car turned up.’

Marsh looks at me through narrowed eyes. ‘Why wouldn’t she have put it in the right place at the time?’

I lean on my elbows and press my fingers into my head. ‘God knows. She was in a hurry? She made a mistake? It’s been eighteen years since her sister’s death, and it was pitch dark. She could have taken the wrong path. She would have been exhausted, and maybe the environment had changed, and she didn’t recognize the spot. Or maybe it wasn’t her at all. Maybe she had an accomplice.’

I realize as I’m saying all this how desperate I sound.

‘You really hate her, don’t you, Grace?’