“Yes, but they were still abducted. There’s still a crime to investigate.”

Thrupp ignored her. “Two. The timeline is vague. Three. The witnesses are unreliable. Four. There’s no evidence to charge anyone with intention to harm. Five. GPS has just proved that Dowling’s phone was nowhere near the babies at the time of the abduction. If we carry on, we’re chucking money after nothing.”

“But, sir—”

“I think we need to consider the mother herself for it. Have you looked into that?”

Harper closed her eyes briefly. Stay calm, she thought, make your case.

“I understand all of your points, sir, but you haven’t heard this recording. I think if we have it analysed, then we’ll at least have all the facts to work with.”

He steely-eyed her. “What I think is, that if we have it analysed, we’ll be wasting money and time.”

“Not at all. If we can identify the voice on the tape we’ll at least have ticked all the boxes. We wouldn’t want to drop a case without making sure we’d done all we can, right sir?”

“There’s no reason whatsoever for us to analyse that recording. It is absolutely clear to me that Lauren Tranter saw no one that night but the ghosts in her own head. She was hallucinating. And, if I didn’t know better, I’d say you are, too.”

“But, sir.”

Thrupp drew a long breath. “Mrs Tranter is the only one in the frame for this now. We have to admit that it’s not a criminal investigation. What we’re dealing with is a mental-health event.”

*   *   *