They got their sandwiches to go from a greasy spoon cafe, and demolished them quickly as they drove. Porter’s shirt was a crime scene in its own right, crumbs in his lap and a stray spot of grease the only signs that a sandwich had even existed.

Natasha Barclay’s flat was eerily quiet compared to their last visit. The swarm of crime scene technicians poring over every surface had long since moved on to pastures new. Only the bald patch where the carpet had been cut away to file as evidence, and the dried blood on the wall, gave any hint of what had taken place.

What the hell had actually happened?

Lovers’ quarrel? Drunken fight? Something more planned, premeditated? Had she even known the kind of man Bolton was? He knew it was dangerous to discount the possibility of a third party being involved, but he saw it in Bolton’s eyes. He couldn’t back it up with any evidentiary proof, couldn’t elicit a confession from Bolton, but there had been something in the big man’s smirk at the station. Something that taunted Porter, dared him to come after him. Not that Porter needed any encouragement, but he had to take something else to Campbell, something new, to be allowed to put Bolton in a room again.

The flat felt like it had resumed its slumber, like a coma patient after the hopeful flicker of the eyelids has passed. The lines etched into the layers of dust would soon be filled, like tyre tracks with fresh snow. The curtains were still open, the dated decor looking even more surreal in the cold light of day than it ever had hiding in darkness.

Porter didn’t even know what he hoped to find. He wondered if he’d made the trip back as a reminder that Natasha counted just as much as those who had died more recently. He wouldn’t let her be forgotten for another thirty years, not by her family, and not for the sake of Campbell and his crime stats.

They poked around for another five minutes but found nothing. They had similar luck with showing Bolton’s picture to the older residents. They managed to get an answer at two doors, but both neighbours shook their heads, blank looks in their eyes.

They opted to visit the warehouse down by the river next, saving a visit to the hospital for last. Porter squinted, focusing on the road as the wipers cleared their twin cones, only to be sprayed with a fine mist again in seconds. There was something vaguely hypnotic about the monotony of the swish squeak as they worked tirelessly, and they rode most of the way in silence.