Jonah glanced at his sergeant. ‘There’s a small chance that it’s true. But looked at rationally, he went to a hell of a lot of trouble just to meet up about a job offer.’

‘Agreed,’ O’Malley said. ‘And I’m interested in why he flew from Zurich. He must have driven for two or three hours to get there. I’m going to look up whether there were other flights he could have taken without the long drive.’

‘Yes,’ Jonah said, trying and failing to picture where the two cities were on a map. ‘That’s probably the weirdest part of it.’ He paused for a moment, thinking of the distinctive murder weapon. ‘It might also be worth checking whether there’s a retailer who sells those knives in Zurich.’

‘I’ll get on it,’ O’Malley answered.

‘The blood tests from Louise Reakes are sitting with the lab, aren’t they?’ Jonah went on, thoughtfully.

‘Yup,’ O’Malley said. ‘Also useless until tomorrow.’

‘Unless we work on the good nature of our colleagues,’ Jonah said. He pulled his phone out and dialled Linda McCullough’s number.

There were traffic noises in the background as she picked up.

‘We’re on site at Asylum Green,’ she said, immediately. ‘And we have blood.’

‘Blood?’ Jonah asked, dumbly.

‘Yes, Sheens. You’ll know it as the red stuff that runs through most people’s veins.’

Jonah half smiled as he replied, ‘I’ll look it up.’

‘There isn’t a lot of it. Did your female show any signs of injury?’ McCullough asked.

‘Nothing she showed us,’ Jonah said, thoughtfully, ‘but she mentioned pain in her back, which we’re going to get photographed.’ He glanced up at O’Malley, who nodded. Presumably that was already being sorted by one of the female PCSOs.

‘We’ve got a few personal belongings bagged up, too,’ McCullough went on. ‘They may or may not have anything to do with an attack.’

‘Thanks,’ Jonah said. ‘How long do you think you’ll be there?’

‘Why do I suspect that this question isn’t about my mental health?’ McCullough asked.

‘I have no idea,’ Jonah countered. ‘But we’ve got a blood test for Rohypnol I badly want back, and a non-functioning lab.’

True to form, McCullough complained loudly, and then agreed. ‘I’m still waiting for all those pints you owe me, Sheens,’ she added.

‘Just say the word,’ Jonah replied.

The temperature was now just above freezing, and Hanson was suffering. Even with her coat zipped up to her chin and her hands shoved in her pockets, she was shaking with cold.

‘Should have brought another four or five layers,’ she said to Lightman, as the two of them huddled beneath one of the trees on Asylum Green. Or at least as Hanson huddled. Lightman looked as unaffected by everything as usual.