The mother’s name was Victoria Rose Settle, and the twin boys were Robert and Vincent, born at 0141 and 0147 respectively on 2nd July 1976. Amy found the family easily—a search of Sheffield’s public birth records from that year showed only two sets of identical twins born at the right time, and the other set were female. But, when Harper tried the current listed phone number for Mrs Settle while Amy listened, a man told her that his mother no longer lived there.

“Perhaps you’d be able to pass on a message,” said Harper. “I’d really like to talk to her if possible.”

“Why on earth would the police want to talk to her?”

“She may have some information that could help us in a current case.”

“I doubt that, Sergeant.”

“If you don’t mind, I’d like to ask her anyway.”

“You say this is a current case?”

“That’s right.”

“Then I don’t see how she could help you. She hasn’t even been outside on her own for nearly nine years.”

“This relates to a crime recently committed, but the questions I have are to do with something that happened to your mother during July of 1976. There appear to be some similarities to our case that we’d like to investigate.”

“Nothing happened to my mother in July 1976. Unless you mean having me and Vinny. I expect that kept her pretty busy. But nothing involving any crime, as far as I know. Surely I would know if that was the case?”

Harper felt she wasn’t getting anywhere. Perhaps she should try a different tack.

“Mr Settle. Robert?”

“That’s right.”

“Is it possible she might not have told you about it? That maybe she might not have wanted you to know?”

“Oh,” said Robert, drawing out the sound as he considered. “Well. I suppose. If she … did she commit a crime? She’d probably have kept that to herself.”

Harper left a small pause, enough to cast doubt, but not sufficient to confirm or deny.

“I would rather talk to her about this, if you don’t mind. I can call her directly, if you’ll just give me the number.”

“I’m afraid you won’t be able to. She’s got dementia. Early onset Alzheimer’s. She barely knows who I am anymore.” A small sob escaped from Robert Settle then.

Harper hesitated. She felt bad for him. She could imagine that dementia was a particularly cruel way to lose a loved one. “I’m sorry to hear that. It must be very difficult for you. I’m so sorry to have called out of the blue like this.”

There was a silence. Then Robert said, “Mind you, if it’s something from forty-odd years ago, then I don’t know. Maybe you’ll get something out of her.”

“Really?”