They arrived at the Chinese Bell Tower to find two middleaged men in council overalls sheltering from the downpour. The narrow pillars that supported the elegant roof offered little protection from the scatterings of rain thrown around by the gusty wind, but it was better than being completely out in the open. "I'm looking for Iain Maclean," Mark said, glancing from one to the other.

"That would be me," the shorter of the two said, bright blue eyes sparkling in a tanned face. "And who are you?"

Mark identified them both. "Is there somewhere we can go and get a cup of tea?"

The two men looked at each other. "We're supposed to be tidying up the borders, but we were just about to give up and go back to the greenhouses," Maclean said. "There's no caf¨¦ here, but you could come back with us and we could brew up there."

Ten minutes later, they were squashed into a corner at the back of a large plastic-covered tunnel, out of the way of the other gardeners, whose curious stares quickly subsided once they realized there was no drama happening. The smell of humus hung heavy in the air, reminding Mark of his granddad's allotment shed. Iain Maclean wrapped his large hands round a mug of tea and waited for them to speak. He'd shown no surprise at their arrival, nor had he asked them why they were there. Mark suspected Fraser or Ferguson had warned him.

"We wanted to talk to you about Mick Prentice," he began.

"What about Mick? I've not seen him since we moved south," Maclean said.

"Neither has anybody else," Mark said. "Everybody assumed he'd gone south with you, but that's not what we've been hearing today."

Maclean scratched the silver bristles that covered his head in a neat crew cut. "Aye well. I'd heard folk thought that back in the Newton. It just shows you how willing they are to think the worst. There's no way Mick would have joined us. I don't see how anybody who knew him could think that."

"You never contradicted them?"

"What would be the point? As far as they're concerned I'm a dirty blackleg miner. Nothing I have to say in anybody's defence would carry any weight in the Newton."

"To be fair, it's not just a matter of jumping to conclusions. His wife's had money sent to her on and off since he left. The postmark was Nottingham. That's one of the main reasons everybody thought he'd done the unthinkable."

"I can't explain that. But I'm telling you this: Mick Prentice could no more go scabbing than fly to the moon."

"That's what everybody keeps telling us," Mark said. "But people do things that seem out of character when they're desperate. And by all accounts, Mick Prentice was desperate."

"Not that desperate."

"You did it."

Maclean stared into his coffee. "I did. And I've never been so ashamed all my days. But my wife was pregnant with our third. I knew there was no way we could bring another bairn into that life. So I did what I did. I talked about it with Mick beforehand." He flashed a swift glance at Mark. "We were pals, me and him. We were at the school together. I wanted to explain to him why I was doing it." He sighed. "He said he understood why I was set on going. That he felt like getting out too. But scabbing wasn't for him. I don't know where he went, but I knew for sure it wasn't down another pit."

"When did you know he'd gone missing?"

He screwed his face up as he thought. "It's hard to say. I think it was maybe when the wife came down to join me. So that would make it round about the February. But it might have been after that. The wife, she's still got family back in the Wemyss. We don't go back there. We wouldn't be welcome. Folk have got long memories, you know? But we stay in touch and sometimes they come here for a visit." A pale apology of a smile crossed his face. "The wife's nephew, he's a student at the university down here. Just finishing his second year. He comes round for his dinner now and again. So aye, I heard Mick had gone on the missing list, but I couldn't tell you for sure when I knew."

"Where do you think he went? What do you think happened?" In his eagerness, Mark forgot the cardinal rule of asking only one question at a time. Maclean ignored both of them.

"How come you're interested in Mick all of a sudden?" he said. "Nobody's come looking for him all these years. What's the big deal now?"

Mark explained why Misha Gibson had finally reported her father missing. Maclean shifted awkwardly in his seat, his coffee slopping over his fingers. "That's hellish. I mind when Misha was just a wee lassie herself. I wish I could help. But I don't know where he went," he said. "Like I said, I've not seen hide nor hair of him since I left the Newton."

"Have you heard from him?" Otitoju chipped in.

Maclean gave her a flat hard look. On his weatherbeaten face, it rested as impassive as Mount Rushmore. "Don't get smart with me, hen. No, I haven't heard from him. As far as I'm concerned, Mick Prentice fell off Planet Iain the day I came down here. And that's exactly what I expected."

Mark tried to rebuild the rapport, injecting sympathy into his voice. "I understand that," he said. "But what do you think happened to Mick? You were his pal. If anyone can come up with an answer, it would be you."

Maclean shook his head. "I really don't know."

"If you had to hazard a guess?"

Again he scratched his head. "I tell you what. I thought him and Andy had taken off together. I thought they'd both had enough, that they'd buggered off somewhere else to start all over again. Clean sheet, and that."

Mark remembered Prentice's friend's name from the briefing document. But there had been no mention of them leaving together. "Where would they go? How could they just disappear without a trace?"

Maclean tapped the side of his nose. "Andy was a Commie, you know. And that was when Lech Wa.esa and Solidarity was a big deal in Poland. I always thought the pair of them had buggered off there. Plenty of pits in Poland, and that wouldn't have felt like scabbing. No way, no how."

"Poland?" Mark felt as if he needed a crash course in twentieth-century political history.

"They were trying to overthrow totalitarian Communism," Otitoju said crisply. "To replace it with a sort of workers' socialism."

Maclean nodded. "That would have been right up Andy's street. I figured he'd talked Mick into going with him. That would explain how nobody heard from them. Stuck digging coal behind the Iron Curtain."

"It's been in mothballs for a while now, the Iron Curtain," Mark said.

"Aye, but who knows what kind of life they made for themselves over there? Could be married with kids, could have put the past right behind them. If Mick had a new family, he wouldn't be wanting the old one emerging from the woodwork, would he?"

Suddenly Mark had one of those revelatory moments where he could see the wood hidden among the trees. "It was you that sent the money, wasn't it? You put cash in an envelope and sent it to Jenny Prentice because you thought Mick wouldn't be sending her any money from Poland."

Maclean seemed to shrink back against the translucent polythene wall. His face screwed up so tight it was hard to see his bright blue eyes. "I was only trying to help. I've done OK since I came down here. I always felt sorry for Jenny. Seemed like she'd ended up with the sticky end because Mick didn't have the courage of his convictions."

It seemed an odd way to put it, Mark thought. He could have left it at that; it wasn't his case, after all, and he could do without the aggravation pulling at a loose thread might bring. But on the other hand, he wanted to make the most of this posting. He wanted to parlay the position of CID aide into a permanent transfer to the detective division. So going the extra mile was definitely part of the plan. "Is there something you're not telling us, Iain?" he said. "Some other reason Mick had for taking off the way he did, without a word to anyone?"

Maclean drained his coffee and put the mug down. His hands, disproportionately large from a lifetime of hard manual work, clasped and unclasped themselves. He looked like a man uncomfortable with the contents of his own head. He took a deep breath and said, "I suppose it makes no odds now. You can't make somebody pay when they're the wrong side of the grave."

Otitoju was about to break Maclean's silence, but Mark gripped her arm in warning. She subsided, her mouth a compressed line, and they waited.

At last, Maclean spoke. "I've never told anybody this. For all the good keeping schtum's done. You have to understand, Mick was a big union man. And of course, Andy was a full-time NUM official. Feet under the table, well in there with the top men. I don't doubt Andy told Mick a lot of things he maybe shouldn't have." He gave a wan smile. "He was always trying to impress Mick, to be his best pal. We were all in the same class at school. The three of us used to hang about together. But you know how it is with threesomes. There's always the leader and the other two trying to keep in with him, trying to edge out the other one. That's how it was with us. Mick in the middle, trying to keep the peace. He was good at it too, clever at finding ways to keep the pair of us happy. Never letting either one of us get the upper hand. Well, not for long anyway."

Mark could see Maclean relaxing as he remembered the relative ease of those early days. "I know just what you mean," he said quietly.

"Anyway, we all stayed pals. Me and the wife, we'd go out in a foursome with Mick and Jenny. Him and Andy would play football together. Like I said, he was good at finding things that made the both of us feel like we had a wee bit of something special. So anyway, a couple of weeks before I came away down here, we spent the day together. We walked along to Dysart harbour. He set up his easel and painted, and I fished. I told him what I had planned and he tried to talk me out of it. But I could tell his heart wasn't really in it. So I asked him what was bothering him." He stopped again, his strong fingers working against each other.

"And what was it?" Mark said, leaning forward to close Otitoju's stiff presence out of the circle, to make it a male environment.

"He said he thought one of the full-time officials had his hand in the till." Then he locked eyes with Mark, who could sense the terrible betrayal that lay behind Maclean's words. "We were all skint and starving, and one of the guys who was supposed to be on our side was lining his own pockets. It might not sound like a big deal now, but back then, it shook me to the very core."

Thursday, 30th November 1984; Dysart

A mackerel was tugging at his line, but Iain Maclean paid it no mind. "You're fucking joking," he said. "Nobody would do that."

Mick Prentice shrugged, never taking his eyes off the cartridge paper pinned to his easel. "You don't have to believe me. But I know what I know."

"You must have misunderstood. No union official would steal from us. Not here. Not now." Maclean looked as if he was going to burst into tears.

"Look, I'll tell you what I know." Mick swept his brush across the paper, leaving a blur of colour along the horizon. "I was in the office last Tuesday. Andy had asked me to come in and help him with the welfare requests, so I was going through the letters we'd had in. I tell you, it would break your heart, reading what folk are going through." He cleaned his brush and mixed a greenish grey colour on his pocket-sized palette. "So I'm going through this stuff in the wee cubbyhole off the main office, and this official is out front. Anyway, some woman came in from Lundin Links. Tweed suit, stupid mohair beret. You know the kind- Lady Bountiful, looking out for the peasants. She said they'd had a coffee morning at the golf club and they'd raised two hundred and thirty-two pounds to help the poor families of the striking miners."

"Good for them," Maclean said. "Better going to us than Thatcher's bloody crew."

"Right enough. So he thanks her and off she goes. Now, I didn't actually see where the money went, but I can tell you it didn't go in the safe."

"Aw, come on, Mick. That proves nothing. Your guy might have been taking it straight to the branch. Or the bank."

"Aye, right." Mick gave a humourless laugh. "Like we put money in the bank these days when the sequestrators are breathing down our neck."

"All the same," Maclean said, feeling offended somehow.

"Look, if that was all, I wouldn't be bothered. But there's more. One of Andy's jobs is to keep a tally of money that comes in from donations and the like. All that money's supposed to be passed through to the branch. I don't know what happens to it then, whether it comes back to us as handouts or whether it ends up at the court of King Arthur, salted away in some bloody Swiss bank account. But everybody that collects any money is supposed to tell Andy and he writes it up in a wee book."

Maclean nodded. "I remember having to tell him what we made when we were doing the street collections back in the summer."

Mick paused briefly, staring out at the point where the sea met the land. "I was at Andy's the other night. The book was sitting on the table. When he went to the toilet, I took a wee look. And the donation from Lundin Links wasn't there."

Maclean jerked so roughly on his line that he lost the fish. "Fuck," he said, reeling in furiously. "Maybe Andy wasn't up to date."

"I wish it was that simple. But that's not it. The last entries in Andy's book were four days after that money was handed in."

Maclean threw his rod on the stone flags at his feet. He could feel tears pricking his eyes. "That's a fucking disgrace. And you expect me to feel guilty about going to Nottingham? At least that's an honest day's work for an honest day's pay, not stealing. I can't believe that."

"I couldn't believe it either. But how else can you explain it?" Mick shook his head. "And this is a guy who's still on a wage."

"Who is it?"

"I shouldn't tell you. Not till I've decided what I'm going to do about it."

"It's obvious what you've got to do. You've got to tell Andy. If there's an innocent explanation, he'll know what it is."

"I can't tell Andy," Mick protested. "Christ, sometimes I feel like walking away from the whole fucking mess. Drawing a line and starting again someplace else." He shook his head. "I can't tell Andy, Iain. He's already depressed. I tell him this, it could send him over the edge."

"Well, tell somebody else. Somebody from the branch. You've got to nail the bastard. Who is it? Tell me. A couple of weeks, I'm going to be out of here. Who am I going to tell?" Maclean felt the need to know burning inside him. It was one more thing that could help him believe he was doing the right thing. "Tell me, Mick."

The wind whipped Mick's hair into his eyes, saving him from the desperation in Maclean's face. But the need to share his burden was too heavy to ignore. He pushed his hair back and looked his friend in the eye. "Ben Reekie."

Friday, 29th June 2007; Glenrothes

Karen had to admit she was impressed. Not only had the Nottingham team done a great job, but DC Femi Otitoju had typed up her report and e-mailed it in record time. Mind you, Karen thought, she'd probably have done the same in her shoes. Given the quality of the information she and her partner had been able to extract, any officer on CID trial would be desperate to make the most of it.

And there was something here to make the most of. DC Otitoju and her oppos had found out who had been muddying the waters by sending money to Jenny Prentice from Nottingham. And crucially, she'd also given the first possible answer to the question of who might be happy to see the back of Mick Prentice. Feelings were running high by then, the union growing in unpopularity in many quarters. Violence had erupted more times than anyone could count, and not always between police and strikers. Mick Prentice could have found himself consumed by the fire he was playing with. If he'd confronted Ben Reekie with what he knew; if Ben Reekie was guilty as charged; and if Andy Kerr had been dragged into the affair because of his connection to the other two, then there was motive for getting rid of both of the men who had gone missing around the same time. Maybe Angie Kerr had been right about her brother. Maybe he hadn't killed himself. Maybe Mick Prentice and Andy Kerr were both victims of a killer-or killers-desperate to protect the reputation of a crooked union official.

Karen shuddered. "Too much imagination," she said out loud.

"What's that?" Phil dragged his eyes from the computer screen to frown at her.

"Sorry. Just giving myself a telling off for being melodramatic. I tell you, though, if this Femi Otitoju ever fancies a move north, I'd swap her for the Mint so fast it would make his eyes water."

"Not that that's saying much," Phil said. "By the way, what are you doing here? Shouldn't you be talking to the lovely Miss Richmond? "

"She left a message." Karen glanced at her watch. "She'll be here in a wee while."

"What's the hold-up been?"

"Apparently she had to talk to some newspaper lawyer about an article she wrote."

Phil tutted. "Just like Brodie Grant. Still think we're the servant class, that lot. Maybe you should keep her waiting."

"I can't be bothered getting into stupid game playing. Here, have a look at this. The paragraph I've highlighted." She passed Otitoju's report over to Phil and waited for him to read it. As soon as he lifted his eyes from the page, she spoke. "That's a sighting of Mick Prentice a good twelve hours after he walked out of the house. And it sounds like he wasn't himself."

"It's weird. If he was taking off, why was he still hanging around at that time of night? Where had he been? Where was he going? What was he waiting for?" Phil scratched his chin. "Makes no sense to me."

"Me neither. But we're going to have to try and find out. I'll add it to my list." She sighed. "Somewhere below having a proper conversation with the Italian police."

"I thought you'd spoken to them?"

She nodded. "An officer at their headquarters in Siena, some guy called Di Stefano that Pete Spinks in Child Protection dealt with a couple of years back. He speaks pretty good English, but he needs more info."

"So you'll be looking at Monday now?"

Karen nodded. "Aye. He said not to expect anybody in their office after two o'clock on a Friday."

"Nice work if you can get it," Phil said. "Speaking of which, do you fancy a quick drink after you're finished talking to Annabel Richmond? I've got to go round to my brother's for dinner, but I've time for a swift half."

Karen was torn. The prospect of a drink with Phil was always enticing, but her absence from the office meant that her admin load had gone unattended for too long. And she couldn't catch up tomorrow because they were off to the caves. She toyed with the idea of slipping out for a quick drink, then coming back to the office. But she knew herself well enough to know that once she'd escaped from her desk she would find any excuse to avoid returning to the paperwork. "Sorry," she said. "I need to clear the decks."

"Maybe tomorrow, then? We could treat ourselves to lunch at the Laird o' Wemyss."

Karen laughed. "Have you won the pools? Do you know what that place costs?"

Phil winked. "I know they have a special deal for lunch on the last Saturday of the month. Which would be tomorrow."

"And I thought I was the detective round here. OK, you've got a deal." Karen turned her attention back to her notes, making sure she knew exactly what to ask Annabel Richmond.

Karen's phone rang five minutes before the agreed time. The journalist was in the building. She asked a uniform to show Richmond to the interview room where she'd met Misha Gibson, then gathered her papers together and headed downstairs. She walked in to find her witness leaning on the window sill and staring out at the thin strands of cloud stretched across the sky. "Thanks for coming in, Miss Richmond," Karen said.

She turned, her smile apparently genuine. "It's Bel, please," she said. "I should be thanking you for being so accommodating. I appreciate your flexibility." She crossed to the table and sat down, fingers intertwined, seeming relaxed. "I hope I'm not keeping you late."

Karen wondered when she'd last been home at five on a Friday and couldn't come up with an answer. "I wish," she said.

Bel's laugh was warm and conspiratorial. "Tell me about it. I suspect your work culture is scarily similar to mine. I must say, by the way, that I'm impressed."

Karen knew it was a ploy but rose to the bait anyway. "Impressed by what?"

"Brodie Grant's pulling power. I didn't imagine I'd be dealing with the woman who put Jimmy Lawson behind bars."

Karen felt the blush rising up her neck, knew she'd be looking blotchy and ugly, and wanted to kick the furniture. "I don't talk about that," she said.

Again that mellow, inviting laugh. "I don't imagine it's a popular topic of conversation between you and your colleagues. It must make them watch their backs, knowing you were responsible for pinning three murders on your boss."

She made it sound as though Karen had fitted Lawson up. In truth, once she'd been invited to think the unthinkable, the evidence had been there for the finding. One twenty-five-year-old rape and murder, two fresh kills to cover that past misdemeanour. Not nailing Lawson would have been the fit-up. It was tempting to tell Bel Richmond just that. But Karen knew that responding would start a conversation that could only go places she didn't want to revisit. "Like I said, I don't talk about it." Bel cocked her head, gave a smile that Karen read as rueful but confident. Not a defeat but a delay. Karen's smile was inward, knowing the journalist was wrong on that score.

"So, how do you want to do this, Inspector Pirie?" Bel said.

Stolidly refusing to be seduced by Bel's charm, Karen kept her voice official. "What I need right now is for you to be my eyes and ears and take me through what happened, step by step. How you found it, where you found it. The whole story. All the details you can remember."

"It started with my morning run," Bel began. Karen listened carefully as she told the story of her discovery again. She took notes, jotting down questions to ask afterwards. Bel appeared to be candid and comprehensive in her account, and Karen knew better than to break the flow of a helpful witness on a roll. The only sounds she made were wordless murmurs of encouragement.

At last Bel came to the end of her story. "To be honest, I'm surprised you recognized the poster right away," Karen said. "I'm not sure I would have."

Bel shrugged. "I'm a hack, Inspector. It was a huge story at the time. I had just reached the age where I thought I might like to be a journalist. I'd started paying proper attention to newspapers and news bulletins. More than the average person. I guess the image lodged in the deep recesses of my brain."

"I can see how that would happen. But, given that you understood the significance of it, I'm surprised you didn't bring it straight to us rather than Sir Broderick." Karen let the unspoken accusation lie in the air between them.

Bel's answer came smoothly. "Two reasons, really. First, I had no idea who to contact. I thought if I just walked into my local police station it might not be treated very seriously. And second, the last thing I wanted to do was to waste police time. For all I knew, this was some sick copy. I reckoned Sir Broderick and his people would know at once whether this was something that ought to be taken seriously."

Slick answer, Karen thought. Not that she expected Bel Richmond to admit any interest in the substantial reward Brodie Grant still offered. Nor in the prospect of gaining unrivalled access to the ultimate source. "Fair enough," she said. "Now, you said you had the impression that whoever had been living there had cleared out in a hurry. And you told me about what looked like a bloodstain in the kitchen. Did it seem to you that the two things were connected?"

A moment's silence, then Bel said, "I'm not sure how I would be able to make a judgement about that."

"If the stain on the floor was old, or it wasn't blood, it could be part of the landscape. Chairs sitting on it, that sort of thing."

"Oh, right. Yes, I hadn't thought of it in those terms. No, I don't think it was part of the scenery. There was a chair overturned near it." She spoke slowly, obviously summoning the scene in her mind. "One section looked like someone had tried to clean it up then realized it was pointless. The floor's made of stone slabs, not glazed tiles. So the stone soaked up the blood."

"Were there any other posters or printed material?"

"Not that I saw. But I didn't search the place. To be honest, the poster freaked me out so much I couldn't wait to get out." She gave a little laugh. "Not really the image of the intrepid investigative hack, am I?"

Karen couldn't be bothered bolstering her ego. "The poster freaked you out? Not the blood?"

Again a pause for thought. "You know something? That hadn't occurred to me till now. You're right. It was the poster, not the blood. And I don't really know why."

Saturday, 30th June 2007; East Wemyss

The sea wall was new since Karen had last visited East Wemyss. She'd deliberately arrived early so she could take a walk around the lower part of the village. They'd sometimes walked along the foreshore between there and Buckhaven when she'd been a kid. She remembered a run-down fag-end of a place, shabby and forlorn. Now it was spruced up and smart, old houses recently harled white or sandstone red and new ones looking fresh out of the box. The deconsecrated church of St. Mary's-by-the-Sea had been saved from dilapidation and turned into a private home. Thanks to the EU, a sea wall had been built with sturdy blocks of local stone to hold the Firth of Forth at bay. She walked along the Back Dykes, trying to get her bearings. The woodland behind the manse was gone, replaced by new houses. Same with the old factory buildings. And the skyline ahead of her was transformed now the pit winding gear and the bing were gone. If she hadn't known it was the same place, she'd have been hard pressed to recognize it.

She had to admit it was an improvement, though. It was easy to be sentimental about the old days and forget the appalling conditions so many people were forced to live in. They were economic slaves too, trapped by poverty into shopping only at the local establishments. Even the Co-operative, supposedly run for the benefit of its members, was pricey compared to the shops in Kirkcaldy High Street. It had been a hard way of life, the community spirit its only real compensation. The loss of that small offset must have been a killer blow for Jenny Prentice.

Karen turned back towards the parking lot, looking along the seashore to the striated red sandstone bluff that marked the start of the string of deep caves huddled along the base of the cliff. In her memory, they were quite separate from the village, but now a row of houses butted right up against the outside edge of the Court Cave. And there were information boards for the tourists, telling them about the caves' five-thousand-year history of habitation. The Picts had lived there. The Scots had used them as smithies and glassworks. The back wall of the Doo Cave was pocked with dozens of literal pigeonholes. Down through time, the caves had been used by the locals for purposes as diverse as clandestine political meetings, family picnics on rainy days, and romantic trysts. Karen had never dropped her knickers there, but she knew girls who had and thought none the worse of them for it.

Walking back, she saw Phil's car draw up where tarmac gave way to the coastal path. Time to explore a different conjunction of past and present. By the time she reached the parking lot, Phil had been joined by a tall, stooped man with a gleaming bald head, dressed in the kind of jacket and trousers that the middle classes had to buy before they could attempt any walk more challenging than a stroll to the local pub. All zippers and pockets and high-tech materials. Nobody Karen had grown up with had special clothes or boots for walking. You just went out for a walk in your street clothes, maybe adding an extra layer in the winter. Didn't stop them doing eight or nine miles before dinner.

Karen mentally shook herself as she approached the two men. Sometimes she freaked herself out, thinking like her granny. Phil introduced her to the other man, Arnold Haigh. "I've been secretary of the Wemyss Caves Preservation Society since 1981," he said proudly in an accent that had its roots a few hundred miles south of Fife. He had a long thin face with an incongruous snub nose and teeth that gleamed an unnatural white against weatherbeaten skin.

"That's real dedication," Karen said.

"Not really." Haigh chuckled. "No one else has ever wanted the job. What exactly is it you wanted to talk to me about? I mean, I know it's Mick Prentice, but I haven't even thought of him in years."