He took Laura’s tea to her and found her sitting up, still looking pensive.

‘You’re starting to really worry me, sweetheart,’ he said softly. ‘Isn’t there anything I can do to help?’

Laura smiled at him. ‘I’m so sorry. I never meant to worry you, darling. But now I have Sam and another expert in the field with me, I’m sure we’ll sort it in no time.’

‘And that’s all it is? Nothing else?’ he asked.

For one fleeting second there was an expression of . . . what? Surely not guilt. Or maybe just tension, and then it was gone. But he was a policeman, trained to notice such indications.

‘It’s just work, really it is.’ She held out her arms to him.

He lay down and put his arms around her. She wasn’t telling the truth. He was determined to ring Sam as soon as possible.

* * *

Sam was sitting up in bed with a large mug of decaffeinated tea — for his heart — surrounded by Hughie Mackenzie’s case studies. It was heavy stuff. By far the most shocking was the brutal attack on an apparently well-loved sister and her husband. But there were other cases too, ones that hadn’t made the tabloids. He read about a young man who in his waking life had no real creative talent, but in his sleep he produced the most beautiful and elaborate artwork. He had even held exhibitions in famous galleries. Hughie had included copies of some of his work, which was truly amazing. Apparently, an art expert had been shown a selection of this artist’s nocturnal paintings and had believed each one to have been made by a different artist, so varied were they in technique and style.

Sam sipped his tea and turned a page. He read of a chef who would get up in the night and prepare a full meal. His wife would find him eating, still fast asleep. Amusing, but think of those sharp knives being wielded by a sleeping man.

Hughie was right, parasomnia was a fascinating phenomenon. Some people suffered terrifying hypnagogic hallucinations, where a person believes they can see a mysterious stranger standing at the foot of the bed. Others acted out their dreams — people had been observed dancing barefoot in the rain. Some raided the fridge, and then when awake, wondered where yesterday’s leftovers had gone. A few drove in their sleep. Others had sex. A rare disorder called sexsomnia had been used as a defence in rape cases. What they all had in common was the fact that they had sleepwalked as children.

Sam pushed the papers aside and leaned back against the pillows, his mug in both hands. He knew about some of these conditions, but because they were usually assumed to be medical or drug-induced, no cases had come to his personal attention, so he wasn’t surprised that Laura hadn’t met one either. He was to meet her today at the mill to discuss her observations. She had said there was something about Shields that she found disconcerting, but she could not pinpoint what it was. It was this that had sent her to him for help. She wanted Sam to meet Freddie Shields so he could observe him in person and help her understand why she felt this way.