‘But,’ she continued, ‘it can happen in woodland situations like this, where there’s a lot of wildlife.’

‘Fair point,’ he said, swallowing back those memories of past bodies he’d seen, picked clean. He didn’t want these memories right now. He looked down at the row of evidence bags. In one was a popsock; another contained a headband; another, a substantial kitchen knife.

He picked up the bag with the knife in his gloved hand and held it out in the daylight. There was dried blood on the blade and handle. ‘This is the knife that was found in a bush nearby, Lorna?’

‘Yes, it is. I’ve sent a picture of it back to the incident room to see if they can get a match with the set of knives in the kitchen of the house.’

‘Can I see the bush?’

She led Grace and Branson a short distance from the metal track and stopped at a yellow triangle on the ground. It was marked ‘7’ and was right in front of a tangle of brambles, with ripe blackberries on the branches.

‘It was in there.’

Grace studied the bush and then looked around. There were several more similar bushes nearby, but each of these much bigger and far denser. He frowned, looked at Branson for a moment, then back at the surrounding bushes.

‘Seeing something I’m not, boss?’ the DI asked.

‘Something that’s not making total sense,’ Grace said. ‘Why this bush?’

‘Because it’s close to the grave,’ Branson suggested.

Grace fixed his gaze on him. ‘OK, think about it for a moment. I always try to put myself in the killer’s shoes. Let’s hypothesize that Niall Paternoster murdered Eden, dismembered her body, drove the remains out here to a grave, along with the clothes she had been wearing when he killed her, and interred her in this grave. Why didn’t he put the knife in with her?’

Glenn Branson frowned in thought. ‘Animals? Or maybe he was in a red mist. Like all crims in the aftermath? Right? So he brings her out here in the early hours of Friday, he’s all ramped up. Buries her and all the clothing, covers the grave over and then – shit! He realizes he’s forgotten to bury the knife. So he discards it in the first bush he sees?’

‘A simple, stupid error,’ Lorna Dennison-Wilkins said. ‘Seen it before many times. The killer in a panic.’

Grace shook his head. ‘This doesn’t fit. He wasn’t in a panic. So, let’s suppose he was planning to murder Eden. The trigger was the row they had last Thursday night. Maybe he deliberately created the row.’

‘But isn’t that a bit daft?’ Branson asked. ‘Wouldn’t he have known the neighbours would hear?’

‘Not necessarily. If he’s a narcissist, bigger on ego than he is on brains as you and I both thought after talking to him, perhaps he thought that the neighbours hearing a row would lend credence to the story he’s giving that she’s left him – done a runner on their marriage. But without thinking through how all his movements would be picked up on ANPR cameras and GPS tracking of his phone.’ Grace shrugged. ‘That wouldn’t be the first time a killer’s been trapped that way.’