Corstorphine felt a chill run down his spine, settling in his stomach like a lead weight. He needed to look at that video again. “Can you get back to me with anything you find?”

The voice on the other end of the line paused. “We’ve been told you’re off the case, Corstorphine. The ACC was quite specific about that yesterday.”

“I haven’t been told anything official, so as far as I’m concerned I’m still working the case. Just send me what you find and if I’m no longer involved then I won’t bother looking at it.”

“OK.” The response was dubious. “Soon as we hear anything I’ll be in touch. I’ll pass on your comments about swapping the headrest to the Inverness detectives. They’re handling Lord Lagan’s murder.”

As soon as the line went dead Corstorphine ran the CCTV footage again. Just as she raised her hand towards the camera, he could see her fingers waving one after the other before the picture was flooded with light. He was glad he was alone, sitting at his desk – he was fairly certain he knew now who the murderer was. Opening his desk drawer, he pulled out the print Frankie had given him; a newspaper article about the innovative French clockmaker, Henri Dupont. The photograph of the Toulouse clockmaker showed him standing behind some animatronic construction made from bone but there, to the side, was a girl standing almost lost in the shadows. He’d never checked the date – Henri Dupont had died five years ago. With a sinking feeling Corstorphine searched online, pulling up the same photograph and reading the date. 2002. Abigail Stevens would have been about eleven years old – around the same age as the girl in the photograph. On a whim, he searched for the meaning of her name. Abigail – my father’s joy. Like clockwork, Corstorphine’s memory returned the French for joy – joie. Joie Dupont. It couldn’t be coincidence! June Stevens had never provided the name of her daughter’s father, yet Brian had told him he’d taken her far away where she’d be safe. Had the old detective managed to track down the girl’s father, taken her to France to start a new life? Could it be that she and her father had plotted revenge on her mother’s murderers, or was he taking this too far? Either way, he had no real evidence, just the coincidence of a characteristic wave and a feeling from deep in his gut.

His phone rang and he recognised the same ebullient forensics officer from earlier.