‘The other thing he told us, having somehow just remembered,’ Rhona said, ‘was that the clothes Mary had been wearing before her confirmation were missing from her home.’

‘That’s weird. Could she have taken them with her? But why would she do that?’ Chrissy mused further. ‘Her house was opposite the school.’

‘Maybe she didn’t plan on going straight home,’ Rhona said, ‘and didn’t want to spoil her dress?’

‘God, I was terrified of messing my frock. Mainly because my mum had warned me to within an inch of my life that my Aunt Annie would have my guts for garters. And, believe me, Annie was one scary woman.’

‘If Mary had planned to go to her den . . .’ Rhona said.

‘Karen, her bosom buddy, would know if that was the case.’

Rhona nodded. The idea of not going to Stirling, having irked her from the beginning, now became major.

As usual, Chrissy was observing her thought processes.

‘You’re going up there,’ she said.

‘Can you manage on your own?’

‘Of course. But before you go, describe the missing clothes,’ Chrissy said.

‘A hand-knitted blue woollen jumper, a grey pleated skirt, white ankle socks, plus a pair of leather sandals,’ Rhona told her. ‘All circa 1975.’

‘I’ll make a start on the fibres you took from the body.’

‘And I’ll let DS Jones know I’m on my way.’

Now past mid-morning, the road out of Glasgow was quiet, which gave Rhona the opportunity to think. For Karen Marshall to disappear so swiftly after she’d just been located suggested she didn’t want to be found, or alternatively, someone hadn’t wanted her to get in touch with the police.

Rhona wondered how many people outside those in the recovery cafe had known about the diary. The press certainly hadn’t learned about it or it would have been a front-page splash, whether the diary contained key information on Mary McIntyre’s murder or not. The fact that the press hadn’t got hold of the diary story was a tribute to the support group who’d stayed loyal in their silence.

But, Rhona thought, as she approached the single-track road that led to Rowan Cottage, Karen Marshall’s home address couldn’t be kept a secret any longer. That was obvious from the existence of the barrier at the road end, together with the attending police officer.

She rolled down her window and told him who she was.

‘DS Jones said you were on your way, Dr MacLeod. Go on up. I’m just keeping the local press and other interested parties at bay. Although we’ve already had a drone from King’s Knot come for a look.’

Thick gorse bushes, some already starting to bloom in the milder weather of the last few days, blanked any view Rhona may have had of the cottage and its immediate surroundings. Only the castle rose like a sentinel in the near distance. Assuming Karen had left either on foot or in a vehicle, it was unlikely that she’d been seen on this road.