Shame flooded Joanna at the fact that she didn’t know this much about her own … what was she? Sister had always felt wrong. Why hadn’t she admitted that before now? Hi, Sis, she used to say when they met, but it wasn’t sincere, hadn’t been for years. Sister had become a kind of dark joke shared between them and in front of Marianne. The word stood in place of what they wanted to say to each other, a poor substitute, a thing they’d both been forced to accept.

Jo knelt down to search under the bed.

“Oh no,” she said.

“What have you found?” said Atkinson, dropping to his knees to see.

She pulled it out and unzipped the case. Under a yellow duster that had never seen dust, had only ever been used to lovingly polish the instrument’s curves, was the burnished form of Ruby’s violin. Jo stared at it, letting the significance of it being here sink in.

Atkinson said, “Are you okay?”

“She never leaves this thing anywhere,” she said. “It’s like a child to her.” Or it used to be, thought Joanna. Things must have gone really badly wrong for Ruby to abandon her violin.

“Are you going to tell me, then?”

“Tell you what?”

“Whose place this is? Or do I have to guess?”

“It’s Ruby’s place.”

“Your sister, Ruby?”

She looked at the carpet. Then she nodded.

In the kitchen, she and Atkinson stared across at the big window onto Gregor’s flat. It was dark in there, the open curtains offering nothing more than a vague impression of the plush living space they’d searched the day before.

“Can I ask you something, boss?”

“Sure,” said Joanna.

“Why haven’t you told the DI that your sister lives here?”

“It’s not relevant.”

“But the address is already part of the investigation. I can see now why you wanted to take the statement yourself, but there’s nothing stopping one of the team looking up who lives here. Louise seemed keen to start digging.”

“Louise isn’t going to make that link. Harper’s a common enough name.”

“I think you’re underestimating Louise. And me, actually.”

She looked at him. “Fine, maybe it might be relevant to the case, but I want to find her first, talk to her. Give her a chance to explain.”

“Explain what?”

“Where she’s gone. Why she left. She won’t answer her phone, Steve—she won’t talk to me. Hasn’t for months. I think she’s changed her number.”

“Hang on, this has been going on for months? How long has she been missing?”

“I didn’t realize she was missing until today. I thought she was still avoiding me. There was a big family bust-up. I haven’t spoken to her since October.”