As they had driven the farmer home, Albone had explained his family’s century-old tenure at the farm where he’d grown up, also taking on his late father’s self-appointed mantle as community protection officer, especially of the historic ruin at Cold Christmas. Except where Albone Senior had cut grass and cleaned graffiti, his son adopted a more pragmatic approach.

Yet despite his flagrant use of a weapon, Hawkins now believed his assertion that he’d intended to miss. Her focus was on catching killers, not marauding yokels with scores against allegedly negligent parish councils.

The MO didn’t tally, either.

Everything about the farmer was aptly rural, from wax jacket to accent, ruddy complexion to ruddy views. Picturing him with a defibrillator was like a Hell’s Angel arranging flowers; a priest playing air guitar. And Albone hardly fitted the profile of any serial killer Hawkins had encountered. Generally, those of murderous intent weren’t so easily found: half-cut in pubs with their mates, within spitting distance from the site where he’d fired on not just a police officer, but a number of civilians too. It just wasn’t the behaviour of someone responsible for three cold-blooded murders.

That hadn’t stopped her confiscating the air rifle from his truck, however, plus two more. Or letting Hertfordshire police know who and where he was. The farmer seemed to appreciate her lenience, nevertheless.

They hit the A10, heading south, both comfortable to ride in silence. Hawkins watched the Giulietta’s headlights’ stretching pools of white light, trying to clear her mind. Unfortunately, that allowed her brain to slip its leash and return to the thorny subject of Mike.

She resisted, thumbing the buttons on the Alfa’s steering wheel to prime the system for verbal instruction.

‘Call Amala mobile,’ she commanded, catching Frank’s questioning glance in response.

‘I asked the others to stay late,’ she explained, ‘in case we detained Albone and needed background checks.’ She pulled out to pass slower traffic, touching ninety-five. ‘I’ll tell them they can get off home.’

Amala picked up after a ring and a half. ‘Ma’am. Is everything OK?’

‘We didn’t arrest him, if that’s what you mean,’ she said. ‘Is Chris there?’

‘Yes.’

‘Put me on speaker, would you?’ she asked, waiting for the sergeant to do so before explaining their encounter with Benjamin Albone, and her reasons for letting him sleep off the evening’s excesses at home, rather than in a cell. These days, you had to be wary of arresting suspects without sufficient evidence in the bag. Once you released someone without charge, fresh evidence was required before they could be detained again.

Unless the farmer now disappeared, which would be a clear suggestion of further involvement, they could always go back for him later on.