Pip had been scribbling as Maria spoke, her words slanted, letters trampling each other in her haste to get it all down. She realized Maria had stopped, was waiting for her to speak.

‘Sorry,’ Pip said. ‘So, other than the confession, what evidence did the police have that made them think Billy is DT?’

‘Well, there were a few things,’ Maria said, and Pip could hear shuffling down her end, as though Maria were flicking through papers. ‘The main one was that Billy was the person who found Tara Yates, the final victim.’

‘He found her body?’ Pip asked. She vaguely remembered that now, from one of the podcasts she’d listened to, remembered how they’d framed it as the big twist.

‘Yes. He found her like that. Tape around her ankles and wrists, wrapped around her face. I couldn’t ever imagine seeing another human being like that. It was at work, where he found her. Billy worked for a grounds maintenance company: cutting lawns, trimming hedges, picking up rubbish, that sort of thing. It was early in the morning, and Billy was on the grounds of a manor house, one of his company’s sites, cutting the grass. He spotted Tara in the trees around the edge of the site.’ She cleared her throat. ‘And Billy... well, the first thing he does is run over to her. He thought she might still be alive, couldn’t see her face, you see. He shouldn’t have gone over, should have left her there and called the police straight away. But that’s not what Billy did.’

Maria trailed off.

‘What did he do?’ Pip prompted her.

‘He tried to help her,’ Maria exhaled. ‘He thought the tape on her face was keeping her from breathing, so he started to unwrap it. Touching her and the tape with his bare hands. Then when he realized that she wasn’t breathing anyway, he attempted CPR, but he didn’t know what he was doing, had never learned what to do.’ A small cough. ‘He knew he needed help, so he ran back to the manor and told one of the employees to call the police, to come help him. He had his mobile on him, he just forgot about it in the moment. I guess maybe he was in shock? I don’t know what that does to you, seeing another person like that.’

Pip knew exactly what it did to you, though she could never try to explain it.

‘So, the result of that,’ Maria continued, ‘was that Billy’s DNA, his sweat and saliva, were all over poor Tara. And his fingerprints. Silly boy,’ she said quietly.

‘But the police would have known that was from him discovering the body, trying to save Tara, even if he didn’t realize it was too late and he was only contaminating the scene.’

‘Yes, well, maybe that’s what they believed initially. But, you know, I’ve done a lot of research into serial killers these last few years. I would even go as far to say I am an expert in them now. And with this kind of criminal – DT – it is very common that the killer would try to insert himself into the police investigation somehow. Calling in with ideas or tips, or offering to help in search parties, that sort of thing, even trying to get information to see how safe they are from suspicion. That’s what the police thought this was, eventually. Billy inserting himself into the investigation by discovering Tara’s body, to appear helpful, innocent. Or maybe to cover himself in case he had left any DNA on her while committing the murder.’ Maria sighed. ‘You see now, how everything is twisted to fit the story?’

With a sinking feeling in her gut, Pip realized she had just nodded. No, what was she doing? She didn’t want it to go this way, because if there was a chance Billy was innocent, then... fuck, oh fuck.

Luckily Maria had resumed talking, and Pip didn’t have to listen to the voice in her head any more.

‘Maybe this would have been OK, on its own,’ she said, ‘but there were other details that tied Billy into this whole mess. He knew one of the victims. Bethany Ingham, number three, she was his supervisor at work. He was very sad after he learned about her death, said she was always so nice to him. And the first victim, Phillipa Brockfield, her body was found on a golf course in Beaconsfield. It was another site that had a contract with the company Billy worked at, and Billy was on the team assigned there. His work van was seen driving to the golf course on the same morning Phillipa’s body was left there but, of course, he was just driving to work. And the duct tape... well, it was the exact same kind Billy had access to at work, so...’

Pip could feel that part of her awakening, the spark in her brain, questions rolling over each other, gathering speed. The world slowing as her mind picked up, double pace. She shouldn’t, she knew what this path meant for her, but she couldn’t stop it, and one of the questions came loose.

‘So, all of these details tying Billy to the murders, they’re related to his job,’ Pip said. ‘What’s the name of the company he worked for?’

Too late. Just asking it meant it was already too late for her. That, on some level, she must think it possible, that she might not be speaking to the mother of the DT Killer at all.

‘Yes, that is where the connections seem to come from,’ Maria said, voice even faster now, more excitable. ‘The company is called Green Scene Limited. Scene, not like eyes, like the kind in a film.’

‘Got it, thanks,’ Pip said, writing the name of the company at the bottom of her page. She tilted her head, studied the words from another angle. She thought she recognized the name. From where, though? Well, if the company operated nearby, she’d probably seen its logo on vans driving through Kilton.

‘And how long had Billy worked there?’ Pip asked, as she swiped her finger across her laptop’s trackpad, the screen springing back to life. She typed in Green Scene Ltd Buckinghamshire and hit enter.

‘Since 2007, it was.’

The first result was the company’s website and, yes, Pip did recognize the cone-shaped tree of its logo. An image she knew, that already existed in her brain somewhere. But why? The home page told her about Green Scene’s specialist and awardwinning grounds maintenance services with a slideshow of photos. Lower down the page was a link to another site, its sister company Clean Scene Ltd which offered cleaning services for offices, housing associations and more.

‘Hello?’ Maria said tentatively, breaking the silence, and Pip had almost forgotten she was even there.

‘Sorry, Maria,’ she said, scratching her eyebrow. ‘For some reason, I recognize the company’s name. And I can’t figure out why.’

Pip clicked on the menu item labelled Our Team.

‘Oh, I know why you’ll recognize it, darling,’ Maria said. ‘It’s because the –’

But the page loaded, and the answer was there in front of her, before Maria could say it. A grinning photo of a suited man at the top, introducing the Managing Director and Owner of Green Scene and Clean Scene Ltd.

It was Jason Bell.

‘It’s Jason Bell’s company,’ Pip said on an outward breath, the pieces connecting in her head. Yes, that was it. That’s how she knew it.

‘Yes, dear,’ Maria said softly. ‘Andie Bell’s father, and of course you know all about Andie Bell. We all do now, because of your podcast. Poor Mr Bell was going through his own unthinkable tragedy around the same time.’

Exactly the same time, Pip thought: Andie died on the same night Tara Yates was murdered. And here, Andie had come up yet again, back from the dead. Billy Karras worked at Jason Bell’s company, and his connection to the DT killings in each case was also tied to his job.