‘He’s expecting you.’ She gestured to a door behind her with a waist-high pillar beside it. ‘Hold your visitor ID against the glass panel and the door will open for you. There’s a cubicle on the right where you can suit up. Don’t forget the shoe covers. Dr Myers’ lab is the second on the left. But don’t worry if you forget.’ She pointed to the ID. ‘That’s the only door your ID will open.’

Paula found Dr Dave Myers in a white suit and gloves, filling tiny test tubes from a large syringe, his big brown hands moving with surprising delicacy. He glanced up when she walked in and nodded. ‘Gimme a minute, Paula, while I get this lot started.’ He finished what he was doing and slotted the tray of samples into a tall fridge. While she waited, Paula looked round the lab. She realised she had no idea what most of the equipment was for these days, nor which reagents and stabilisers did what. It was a relief to spot a microscope in the middle of a bench. It felt like Neanderthal technology alongside the other analytical tools.

Amidst the lab equipment were bagged and labelled evidence bags sitting in plastic boxes to avoid any possibility of cross-contamination. Paula recognised Nadia Wilkowa’s clothes from the crime scene; she was pleased to see they’d made it that far up Dave Myers’ priority list.

He closed the fridge and gestured to a lab stool. Paula sat down and he perched next to her, pulling his protective mask down. ‘New facial hair,’ she said, nodding towards a geometrically precise soul patch beneath his lower lip.

He pulled a face at her. ‘Male pogonotrophy is often culturally associated with virility and strength.’

‘But in your case, we’ll make an exception.’

‘You’re not growing more charming with age, Paula,’ he said, clutching at his heart in a mockery of pain.

They’d known each other for years. When Paula had first joined CID, Dave had worked in the police lab, analysing the assorted traces humans left behind them at crime scenes. DNA analysis was in its infancy; Dave and his colleagues were on the cusp of a series of biological breakthroughs that would transform what they could glean from criminal carelessness. It would spawn TV shows whose relationship to reality would be, as always when it came to anything to do with criminal investigation, tenuous at best. It would create unrealistic expectations in both prosecutors and the victims of crime. But it would also produce the kind of evidence that was impossible to argue against. It would take criminals off the streets and put them behind bars. Most importantly, it would promote a conviction among the population that justice was being better served.