Jarvis regarded him silently, frowning with concentration, as if trying to push Cooper towards the path with the force of his gaze. Instead, Cooper held his stare for a moment, then took half a step towards him. The dogs sighed in exasperation and flopped back on to the boards.

‘Of course she’s bloody in,’ said Jarvis.

‘Well, could I perhaps …?’

Jarvis grunted and turned on his heel towards the door of the house. Cooper took it as an invitation to follow. One of the dogs fell in close behind him, sniffing curiously at his heels as if it had found an interesting scent.

An extended search found Geoff Birley sitting in his Audi in a layby two miles away, on the edge of Edendale. He looked almost relieved when a patrol car drew up and two officers checked his identity before putting him into the back seat.

When she heard the news, Diane Fry was still in the Birleys’ house, watching Sandra’s body being prepared for removal. She wondered whether to tell Mr Birley that he’d chosen the Devonshire Estate third option. He’d left his wife exactly where she fell when she died.

At West Street, Fry stood at her desk in the CID room for a few minutes, trying to gather her thoughts. Anxious as she was to question Geoff Birley about the phone calls, it would take some time for him to be processed and ready for interview. They’d probably wait until all the evidence had been collected from the house and statements taken from the neighbours. If he could be placed in the right areas at the times when the calls were made, it might provide evidence of premeditation. The case would be as airtight as possible before they made a move.

There were plenty of other things demanding her attention in the meantime. As always, it was a question of priorities.

Freshest in Fry’s mind was the arson attack on Hudson and Slack. A night-shift worker at one of the industrial units had been loading a truck when the fire had started, and he reported seeing three figures running westwards along the cutting. That was lucky, because most people would have looked at the flames and seen nothing else, especially at night. Everyone loved the sight of a good fire. Uniformed officers were following up the lead, and trying to obtain sightings of a vehicle parked in the streets to the west. That would take time, too.

According to a message he’d left for her, Ben Cooper had met a brick wall with Audrey Steele’s mother on the arson. But her cousin Ellen Walker had been more co-operative. A phone call to her had elicited details of Audrey’s funeral eighteen months ago. The service had been held at St Mark’s in Edendale, but the hearse had taken the coffin on to the crematorium afterwards. Mrs Walker had even remembered who the drivers were – Vernon Slack and Billy McGowan. Full marks to Cooper, then. That was exactly what he’d thought might have happened.