‘Can I come with you?’ Alvis said with obvious enthusiasm, which didn’t please McNab, by the look on his face.

‘You’re on holiday. Remember?’ Rhona reminded him.

The conversation ground to a halt after that. She knew McNab was itching to find out if she had gone to her appointment with Dr Bailey that morning, but there was no way he could bring himself to ask her in front of Alvis. Eventually, Rhona brought the stilted interchange to an end, but not before McNab got the next date set up.

‘I’ll see you then,’ McNab said, meaning I’ll question you then.

‘Over and out,’ Rhona said and switched off the video link on his determined expression.

After Alvis had departed, Rhona walked down to the shore. She and Alvis had talked a little after the Skype conversation with McNab, but not of the true reason why either of them were here on Skye.

He’d spoken of where he might walk tomorrow. That he was staying at the Isles on the square in Portree. That he planned to call in at Portree police station, and make his presence on the island known. Before she’d had a chance to ask why, he’d said, ‘Sergeant Lee MacDonald’s a member of Skye and Lochaber Mountain Rescue Team. I met him in Aviemore when Marita . . .’ He’d tailed off at that, knowing Rhona didn’t require any further explanation.

Rhona looked across the wide and now smooth expanse of the Sound of Sleat towards the snow-capped mainland. This part of Scotland appeared vast and empty, yet the myriad connections between the people who lived here were as intricately spun as a spider’s web and stretched even as far as Norway.

Alvis’s cover had been good, Rhona had to grant him that. He may well have come walking here as an alternative to Cairngorm. But it hadn’t been coincidence that he’d visited the cottage. Chrissy had undoubtedly had a hand in that.

Rhona thought of the worried face of her forensic assistant. After McNab, Chrissy knew her best. Even thinking that made Rhona feel a little guilty, because that put Sean at number three in the list, maybe even four if she brought DI Bill Wilson into the frame.

Bill had been her mentor since she’d started on the job. He’d been there that terrible night in the dingy little room that had smelt of sex and death, when she’d examined the teenage victim of a sexual predator and thought that it might, just might, be the son she’d given up for adoption seventeen years previously.

And yet . . .

It had been Sean who’d encouraged her to find her son. Sean who’d persuaded her that Liam would like her. Sean who’d made the mother-and-son meeting possible, even a success.