“You think those people look evil or unpleasant because you know what they did,” pointed out Nikki. She was sitting on the sofa with her feet tucked under her. She had changed out of her shirt into a big purple jumper, but was still wearing her work tights. There was a ladder in the knee. “Look at Bundy, or Harold Shipman. They looked normal. Shipman looked like a kindly old man, and he’s our most prolific serial killer.”

“Hmm.” Over the last couple of hours, both she and Nikki had taken a crash course in serial killer research. “Bundy. What a cunt.”

“My mum would murder you herself if she heard the language you’re using in front of my porcelain figures. That story though …”

“I know, right?” Heather snatched up one of the remaining prawn crackers and munched on it. “What a weird thing to come out with. And he reckons my mum was a huge fan of these things.” She paused, wondering whether to tell Nikki about the book, then decided against it.

“It’s hard to imagine your mum having much time for grisly fairy tales, I have to admit.”

“Huh. Yeah. And the thing is, it’s a real story. As in, it’s a fairy tale that exists. More or less.”

Nikki paused with a prawn cracker on its way to her mouth.

“It is? How do you know?”

Heather pursed her lips. “I’ve been reading up on the subject—there are a lot of people on the Internet who spend their time analyzing these things. Anyway, the Grimm’s tales have mostly been Disneyfied these days, covered over with sugar and lace and made more palatable, but it seems that once they were every bit as unpleasant as the story Michael Reave told me. The thing is, the Brother and Sister story exists, except he’s changed the ending. In the real story, at the third stream the brother is turned into a deer. And then there’s a lot of quite complicated stuff about kings and princesses, and eventually the witch herself is torn apart by wild beasts. His version was a lot snappier, it has to be said.’

“Oh.” Nikki dipped another prawn cracker into the little plastic container of sweet and sour sauce. “Why do you think he changed it?”

“Lots of these stories got changed, like I said, although not many were changed to be even more violent. Maybe he remembered it wrong, or maybe he was trying to tell me something.” Catching Nikki’s raised eyebrows, Heather shrugged. “He said he’d told me that story to demonstrate that I don’t know everything about my mum. But maybe there was another message, too.”

“That message might well just be ‘I want to freak you out.’ Are you going to go back?”

Heather nodded.

“He knows something, Nikki. He wasn’t surprised at all when I told him what happened to Mum. Maybe they had a pact or something, maybe they were writing in code in the letters.” She trailed off, looking at the darkness outside the windows. “Whatever it is, I need to bloody know.”