At that point he decided to shut up and observe the passing countryside instead.

Having negotiated their departure from Glasgow, they were now heading north-east. Apparently, the wayward cop-turned-soldier-turned-writer hadn’t retired to his home city of Glasgow after leaving Special Forces.

McNab wondered why. Perhaps McCreadie, aka J. D. Smart, hadn’t wanted to bump into old enemies, on either side of the law. That was something McNab could understand. Or maybe it was easier to reinvent himself as a novelist elsewhere.

So he’d taken up residence a little further north. According to the Google map, his current abode was a substantial stone villa on the outskirts of Stirling, just below Castle Hill, with a view over an area of parkland known as King’s Knot.

‘The writing game must be paying off,’ McNab said as they eventually drew up outside.

‘We’re not interested in what he does now.’ Janice pulled on the brake. ‘Just what he knows about our case,’ she reminded him in her usual forthright fashion.

Entering through a wrought-iron gate, the manicured lawn and well-tended flower beds indicated that J. D. Smart was either a keen gardener or else had help in that department.

Which certainly seemed to be the case on the housekeeping front.

Obviously expected, they were shown by a woman McNab presumed was the housekeeper to a conservatory at the rear of the building, which apparently was also the all-important writing room.

Smart McCreadie, as McNab had already fashioned the former detective, rose to greet them from his seat in front of a keyboard and three large screens.

‘DS Clark and DS McNab, I presume?’

They all shook hands, McNab registering the slight tremor in McCreadie’s grip.

‘Dodgy tendons,’ he explained. ‘Viking DNA, I’m reliably informed, although how they continued to wield a sword once the tendon shortened I have no idea. My eyesight’s going too, hence the big screens.’

‘Why three of them?’ McNab asked.

‘I have three different characters’ viewpoints on the go. I switch from one to another as the plot develops. Plus I need to remember what each player knows about the others at any given time.’

‘So, just like a real crime, only with fewer players?’ McNab said, trying to keep sarcasm out of his voice.

By McCreadie’s response, his attempt was unsuccessful.

‘Ah, I see DS McNab is not a fan of the genre. And what about you, DS Clark?’ McCreadie said.

‘I enjoy your books,’ Janice told him. ‘Along with a few other crime authors.’

‘Dare I ask who my rivals are?’

‘You can, but I won’t divulge the names,’ Janice said with a conspiratorial smile (or at least McNab thought that’s what it was).

‘Not giving anything away. I like that,’ Smart McCreadie said with a glance at McNab.

He gestured to a nearby sofa and took a seat himself on a big leather reclining armchair. The spring sun was hitting the glass and there was a scent of something in the air. McNab took it to come from the climber with white flowers that stretched across part of the glass roof above them.