Tut-tut, he thought to himself. Breaking the law. He rubbed a hand across his face. Like everyone else he was wearing latex gloves, bought from a chemist’s shop in Bruntsfield.

‘That’s the last one going in now,’ Allan suddenly piped up, voice half an octave higher than previously.

‘Two-minute countdown,’ Mike stated, lifting his watch to his eyes. Normally he wore a Cartier; other times he carried the antique pocket watch from Bonnar’s. But Allan had suggested something not quite so showy. It had cost less than a tenner from the same chemist’s shop as the gloves, but still seemed to work, though the second hand was now appearing to crawl around the dial. Could the battery be dying on him?

‘Ninety seconds…’

He was trusting Allan’s head count. Didn’t want any other visitors arriving after them…

‘Sixty…’

No backing out now. He found himself glancing in Westie’s direction. Westie was staring back at him, grim-faced or maybe just zonked. His disguise: sunglasses and a woolly hat. The sunglasses were just going on now.

‘Thirty…’

‘Awright, lads, nae fuck-ups,’ one of Chib’s kids was telling the rest of them. Nods and yet more grunts. Adjusting their baseball caps and scarves. Even Gissing was nodding his agreement, hands welded to the steering wheel.

‘Coast clear?’ Mike asked, hoping his voice sounded okay.

‘Clear,’ Allan confirmed.

Mike took a deep breath but couldn’t bring himself to bark the command. Gissing, half turning, seemed to sense this and did it for him.

‘Go!’

The van doors opened with a creak, seven of them moving briskly, turning the corner, coming into the gatehouse guard’s line of sight. Should have staggered it, Mike thought – we look like a gang. One of Chib’s crew was at the front, doing everything but breaking into a jog. Mike had visualised their walk as something like the start of Reservoir Dogs – calm, collected, going to work. But his knees were only just locking. The guard didn’t seem too concerned, however. He had risen from his comfy little chair, sliding open his window and reaching for his clipboard. There was a peaked cap he usually wore, but not today.

‘You’re late,’ he started chiding them. ‘If I can just have your names…’

Turning his head at the sound of his door being opened; brought up short by the sight of the sawn-off appearing from under a jacket; bundled back on to his chair by one of Chib’s lads. The rest of them didn’t pause, kept walking down the path towards the warehouse door. It was to the side of the main loading bay. One of the museum’s vans was parked up, but there was space to squeeze a new arrival next to it. Mike could hear a motorised click behind him and knew it would be the barrier starting to rise.

‘This is it,’ he said, hand gripping the door handle.

‘Let’s do it then,’ he was told.

He pushed open the door and stepped inside. It was just as expected – a warehouse. Plenty of shelving; lots of items smothered in hessian and bubble wrap. Guardroom to the right. The five on-time visitors were being addressed by a member of the gallery’s staff – maybe it was his van outside. He wore a suit and tie and had a name badge on his lapel. One of Chib’s crew was already heading for the guardroom. He walked straight in before lifting out his gun. There were two guards inside, seated at a bank of CCTV screens. Mike watched through the window as their hands went up, eyes fixed on the firearm.

Drawing his own gun, Mike realised it was his turn to speak. Probably only ten or fifteen seconds had passed since he’d opened the door, but it felt like minutes. He had rehearsed the words, rehearsed the voice he would use – gruffer than his own, an instant snarl. Harking back to his roots.

‘Up against that wall, all of you!’

The visitors hesitated, thinking maybe some tasteless practical joke was being played. The staff member had begun to remonstrate, but one of Chib’s remaining two boys stuck the revolver’s barrel against his ear.

‘D’you want your brains splattering the bastardin’ floor?’

The curator didn’t think so. He lifted his hands in surrender and started backing towards the wall, the tour party following his lead.

Mike realised that Allan and Westie were already on the move, striding into the warehouse proper. Mike walked into the guardroom, ignoring the hostage situation, and removed from an already open wall-mounted box the keys he would need. He had memorised the numbers, helped by Professor Gissing, who had also explained that the box was normally kept locked. But not for Doors Open.

There was a split second where one of the numbers escaped him, but he remembered it. Christ, Mike, he told himself, how hard can it be? Only three bloody numbers…

Three vaults. Well, not really ‘vaults’ – Gissing had explained that they were more like walk-in cupboards, but with metal walls. Exiting the guardroom, Mike gave a nod, and the visitors and their guide were marched inside. It would be snug in there. The surveillance cameras were being switched off, the blinds closed. No one would see what was happening – less chance of disguises being noted, physical descriptions tucked away for future reference.

It took Mike longer than expected to find Westie. He thought he knew the layout, but they had reckoned without the additional overflow from the museum on Chambers Street. Some of the pieces were huge, and necessitated detours. Westie rolled his eyes when he saw him. Mike didn’t bother apologising, just tossed him the key, then went in search of Allan. He tried to stay focused – difficult when surrounded by so many treasures. Shelf upon shelf of artefacts, only a few of which were identifiable. Celtic, Mayan, Greek, Roman… no telling just how many cultures and periods were represented. He passed a penny-farthing bicycle and a vast swaddled shape that could have been an elephant. You could spend weeks in here, just as Gissing said, and not have exhausted your sense of wonder. Mike had a sudden thought: this was his first and last visit… he would never be able to come here again. Indeed, it was doubtful the place would ever again open its doors to the general public…

Allan was grinning through a sheen of sweat, and had removed his wig to claw his fingers through his hair.

‘So far so good?’ he asked. Mike felt that the wrong answer would turn his friend to dust. He nodded and handed over the key, while Allan replaced the wig.

‘Did you spot anyone you know in the tour group?’ Mike remembered to ask.

Allan shook his head, dislodging the hairpiece again. ‘Wasn’t really paying attention,’ he apologised.

‘Same here,’ Mike confided, turning in search of his own vault.

It was number 37. The key had a little tag to that effect. Gissing had warned him that the strong rooms were not sequential. To one side of the warehouse lay the even numbers, with the odd numbers on the opposite wall. Crossing the floor at a gap in the shelves, Mike worked his way down the numbered row, tucking his pistol back into his waistband. There were no other guards; no stray visitors. Plenty of cameras, but hopefully turned off. What if Chib’s crew missed one? Allan with his wig off, clawing at his scalp. Too late to be worrying about that. Vault 37. He turned his key in the lock and pulled the heavy door open. It creaked on its hinges only slightly. There was an overhead light inside, just as Gissing had promised. Framed canvases – dozens of them. He knew which numbers he was looking for. The paintings were stored side-on, cocooned in two layers – bubble wrap and cloth – with labels hanging from them. He slid out both paintings and tucked one under each arm before heading back the way he’d come. Lord alone knew what he was leaving behind. Given time, maybe he would have chosen differently. He could feel the Monboddo – it was the smaller of the two. If he had to sprint, he knew which one he’d drop first…