The constable said he would. ‘Glad to, Dr Archer. Good old drunks I can handle, but I’m quite happy to leave the nutcases to you.’

Laura ended the call and sat staring at her phone.

‘Why did you ask about the blood on his clothes?’ asked Sam, taking milk from the fridge.

She didn’t look up. ‘Because that officer never actually saw a wound. What if there was no injury? Suppose he didn’t cut himself that night.’

‘So where did the blood come from?’

‘Exactly.’

They fell silent. Sam was having seriously bad thoughts about Freddie Shields. Thank goodness Laura had come to him rather than try to shoulder the responsibility alone.

‘Let’s take this step by step,’ he said at last. ‘Laura, ring the sleep clinic. We need some expert help. Hughie won’t be here till tomorrow, so let’s see what they’ve come up with.’ He wasn’t expecting much, however. It was quite common for nothing to occur when the sufferer was in different surroundings.

It was a brief call. ‘He never attended,’ she said. ‘He rang saying he was unwell and asked to rebook for tonight. They agreed, but the person I spoke to said they doubted he’d turn up.’

‘Hmm. So, what did he get up to last night?’ Sam said.

‘I dread to think, but—’ Her phone rang.

‘Sorry to call back, Dr Archer. It’s PC Burton here, we spoke a moment ago. I’ve just thought of something one of the other night shift crews mentioned when we came off shift. Someone frightened the hell out of a woman who lives alone. I’m wondering if it could be your bloke.’

‘Really? What did he do?’

‘Pressed his face against the window and scared her badly, but he seemed to have also tried to get into the property by removing a windowpane.’

‘Breaking and entering seems a little extreme for our man, but cases like this can escalate. Who should I ask for if I want to know more, PC Barton?’

‘Either PC Simon Laker or someone from DI Jackman’s team. They attended as it was suspected to be connected to the serious crimes they’re investigating. The murders, that is.’

‘But it wasn’t?’ Laura asked.

‘No. Didn’t fit the suspect’s usual MO, apparently. So, if it was someone else, I thought it might be our fruitcake from the garage.’

Laura thanked him and ended the call. ‘So, we may now know what Mr Shields was doing when he should have been at the sleep clinic.’

Sam kept thinking about the blood on Shields’s clothes. And what of his elderly mother?

‘Sam? Are you up for a house call?’

‘You read my thoughts. The clinic told us he’s unwell—’

‘And because we know how anxious he was to attend, we’re very concerned about him, are we not?’