‘I’m just checking the movements of a few witnesses,’ he said. ‘Some of the people who knew both Archie and Mr Riley. They’re not suspects, not at all, but we just want to eliminate them from our inquiries. I’m sure you understand.’

  ‘You’re checking alibis?’ Her eyes brightened again, but her voice was serious.

  ‘Something like that. A woman came here for lunch the day Mr Riley died. Her name’s Rosalie Greeman. Does that mean anything to you?’

  She shook her head. ‘But if she’s not a regular I’d not know her name.’

  ‘She was wearing a very distinctive coat. Padded, made of brightly coloured patchwork.’

  Perez could see that she was trying as hard as she could to remember. She would have loved to give him an answer. But she shook her head again.

  ‘But I might not have seen. It was so cold outside that we cranked up the heating in here. It was steaming, and people took off their coats as soon as they came in.’

  ‘If she paid by card, you’d have a record on the system?’

  ‘I guess so, but you’d have to ask the manager about that.’ Natalie sounded disappointed because he’d have to consult the boss, because she wasn’t enough for him.

  ‘Can you ask around your colleagues? And if anyone remembers her, give me a ring on this number.’ He handed her his card. It had the station general number, not his direct line. Willow would approve. He was learning that he couldn’t save the world.

  ‘Sure!’ There was that lovely smile again. ‘Sure.’

  The manager had no record of Rosalie Greeman paying for a lunch by card. ‘But that doesn’t mean anything.’ She was a small shrew of a woman. ‘We encourage cash here. Saves us paying the bank fees.’

  He walked back to his car, thinking that he’d wasted most of the day.

  Chapter Twenty-Nine

  IN THE POLICE STATION THE LIGHTS had already been switched on. Ellie was still waiting on news of the Johnsons, and at the same time she was checking sightings of all the Westray folk who’d come in to Kirkwall on the pretext of the cathedral carol service. The A4 notepad in front of her was full of meticulous notes. Like Perez, she preferred paper and a soft lead pencil at work.

  ‘I think better with a pencil,’ she’d say when she was mocked by her tech-addicted colleagues. ‘The ideas come straight from my brain. I don’t need to think what my fingers are doing.’

  Perez joined her, perched on her desk. ‘Any joy? Have you found the Johnsons for me?’

  ‘Not yet.’ She looked up at him. ‘I don’t think they’d stay here in Kirkwall, would they? And I don’t think they’d try to get onto one of the inter-island ferries. They’d stick out as visitors, and I’ve made sure that all the boats have their details. If I were them, I’d drive south, across the barriers. In South Ronaldsay, they’d be close enough to the Pentland ferry terminal in St Margaret’s Hope to get into the Scottish mainland when the heat dies down.’

  ‘Of course. That does make sense.’ The four concrete causeways known as the barriers had been commissioned by Winston Churchill at the beginning of the war after a German U-boat had crawled into Scapa Flow and fired torpedoes at a British battleship, the Royal Oak. Eight hundred and thirty-four men had lost their lives, and the barriers had been built to prevent a similar tragedy. Orcadian kids were brought up on the story. George Riley had probably taught it in his history class, but the children would already have heard it from grandparents, the tale passed down through the generations, just as the Vikings had passed down their tales of heroes and villains.

  Now the barriers linked the four most southerly islands, so there was no need for ferries to cross, and commuting to Kirkwall was much easier.

  ‘I’ve got the word out to as many hotels and B&Bs as I can,’ Ellie said. ‘I’ve contacted Airbnb too. I haven’t had much response from their hosts though. From anyone really. Everyone’s either very busy or they’ve shut down their systems for the holidays. I sent a car down to St Margaret’s Hope to check out that ferry terminal, but there was no sign of their vehicle there.’

  ‘Sounds as if you’ve made terrific progress.’ Perez had hoped for better news, but he didn’t want to upset Ellie again. Not her fault. Nobody could have achieved anything more. ‘How are you getting on with the alibis of the Westray people who were on the mainland when George Riley was killed?’

  ‘There’s one interesting fact. That’s about the Johnsons again.’

  ‘Go on.’

  ‘I went into the Archive cafe this morning.’ She looked at him, a quick grin. He nodded; he liked the place too. It had once been part of the old library. ‘I fancied a proper coffee to keep me going. I showed Gordon behind the bar Johnson’s photo. It was easy enough to get hold of. There are plenty of images of the professor online. Mostly in front of an audience holding forth. Gordon was sure he was in at lunchtime the day of the carol service. Johnson paid with a debit card, and he was able to check the name for me.’ Ellie paused for a moment. ‘It was heaving apparently, but Gordon is absolutely certain that the man was on his own. He could tell me what Johnson ate, and the card record just shows one cover.’

  ‘So no Barbara.’ Perez thought about that. ‘I suppose she could have been shopping and he just didn’t fancy trailing along with her if she was after clothes or local silver.’

  ‘I’d get that if he’d just ordered a coffee,’ Ellie said. ‘But he had a proper meal. You’d wait for your wife before you ate lunch, wouldn’t you?’

  ‘Yeah, I think you would.’ Perez paused for a moment. ‘Do we have a time for when Johnson was eating?’

  ‘Well, we know when he paid the bill.’ Ellie was enjoying herself now. ‘A record is kept on the card machine. Professor Johnson paid and left at one-forty-one.’

  ‘I spoke to a witness this morning who saw George Riley parking his car at the Tormiston Mill between one and one-forty-five.’ Ideas were racing now. He’d always had Johnson down as the prime suspect, not his wife. ‘That might fit. In one way, I guess she had as much to lose in terms of status and income as her man. According to Willow, she loves playing the role of professor’s wife. Perhaps they planned the thing together. Much easier to confuse us if they were working as a couple.’

  ‘Would a woman have the strength to bash him on the head and stuff him into the small burial chamber?’ Ellie was doubtful.

  ‘I’m not sure. I haven’t met her. Lifting him into the chamber would be harder physically than killing him. It would certainly take some nerve to stay there and pose the body. Most people would want to escape from the scene as soon as they could. Barbara works in theatre though – she runs a community arts centre. Perhaps she had a taste for the dramatic.’

  Just, Perez thought, like George Riley.

  Perez called in to the Archive cafe bar before picking up James from the nursery. It was that time when people were switching from coffee to cocktails. For most, it was the last working day before Christmas and people were letting down their hair. At one table there was already singing. At another, a big group of young women were crammed into the bench seats. They wore very little, and their voices were loud, shrill as whistles, piercing the background noise. Gordon was still behind the bar. He was tireless. He’d grown up in North Ronaldsay. Perez had chatted to him about it one day over coffee – North Ronaldsay was the closest Orcadian island to Fair Isle, and they’d compared notes. For Gordon, Kirkwall was the big city, glorious in its variety and attractions. He loved it and had no ambition to move anywhere else.

  ‘I know you spoke to Ellie about this, but why did Professor Johnson stick so clearly in your mind? Because you’d seen him on TV?’

  Gordon laughed. ‘Nah, I never watch TV. Why would I when there’s so much better to do?’

  ‘So why did you remember him so well? Ellie said you were rushed off your feet that day. All those folk in town before the carol service.’

  ‘Because he was such a tosser. One of those guys who can’t help throwing their weight around. You know the sort. Their voices are too loud, they ask too many questions about the menu. Then he complained about the table, even though he was lucky I could squeeze him in at all.’

  ‘That sounds like Johnson.’

  But it also, Perez thought, sounded like a man who wanted to be noticed. A man establishing an alibi, while his wife was committing a murder elsewhere.

  He looked at his watch. Soon it would be time to collect James from nursery and then Willow would be home. He was about to leave the place when he turned back.

  ‘You must have known Nat Wilkinson when you were growing up. He’d be older than you, but not much.’

  ‘Aye, I knew him. His folk ran the North Ronaldsay shop. Came looking for a better life and found they’d brought all their troubles with them. You’ll have met the sort on your fair isle.’

  Perez nodded and smiled.

  ‘The father was a boozer,’ Gordon went on. ‘Secret and steady. He’d disappear out the back of the shop halfway through serving and come back a little calmer and a little brighter. His hand not shaking at all. It was one of those secrets that everyone knew about, but nobody mentioned.’

  Perez nodded again. There’d been secrets like that when he’d been growing up too. ‘Not surprising then that Nat developed an addiction.’

  ‘I don’t think it was his father’s drinking that made him an addict. It was his father’s death.’

  ‘Oh?’ Perez looked at his watch again. He really should be fetching James, but he couldn’t ignore a story like this.

  ‘It was just past midsummer. Nat was already at the grammar school then, but he was home for the holidays. He and his father were fishing from the pier. Sometimes you could get sillocks just by throwing over a line and hook.’ Gordon paused, building the tension and the drama. ‘His dad fell in and drowned. Word was it happened because he was drunk. He must have been kind of wobbly on his feet and he tripped. Nat jumped in and tried to rescue him. Or so he said. There was nobody else with them.’

  ‘You don’t believe it was an accident?’

  Gordon shrugged. ‘The father could be a violent drunk. I’ve seen the bruises on Nat, and his mother was a timid, peedie thing. She wouldn’t have stood up to the man. There was no proof either way, and island folk who knew the family history weren’t going to accuse Nat. If he had helped his father into the water, they wouldn’t have blamed him.’

  ‘You think that was when his problems started?’

  Gordon shrugged. ‘Who knows what sends folk into addiction? Maybe he inherited the gene. But he had a bad time after that. In school, the idea got out that he’d killed his dad. There wasn’t so much shit then on social media, but kids can be cruel face to face too. His nickname was Murd. Short for murderer. George Riley tried to close it all down. He called out the bullies and threatened to expel them. Told their parents, though some of the parents believed the rumours too and didn’t try too hard to stop them. Nat couldn’t escape it. But maybe he tried with the booze and whatever else he could get hold of.’

  There was a moment of silence and then Gordon walked out from behind the bar to take more orders. His customers were becoming impatient. Perez made his way into the busy street to pick up his son, his thoughts racing. Nat Wilkinson was the one Westray man they’d dismissed from their inquiries, because he’d been on the island when George Riley had been murdered. Now, Perez thought, perhaps they should look at him again. Anyone who held on to a secret was interesting.

  He looked at his watch. Willow should be on the ferry on her way in to Kirkwall. Soon she’d be home.

  Perez and Willow talked about Nat Wilkinson later that evening, after they’d had a video call with Cassie. Fran, Perez’s former lover had, in one sense, bequeathed the girl to him, and he thought of her as his own. The girl was fourteen now, with a mind of her own. She’d decided to spend Christmas with her biological father. Perez had been a little hurt when she’d announced that it was all organized and Duncan, her dad, would come in to Orkney to get her on the last day of term. Now he had to admit to himself, a little guiltily, that he was loving this time just with his new family. But he tried to speak to her every day.

  Willow had come home straight off the Westray ferry in time to put James to bed, just as she’d promised. That was when they’d spoken to Cassie, waving at her blurred image on the laptop, listening to her stories of the Shetland family, all the treats that she’d had. It seemed that her father, Duncan Hunter, was enjoying her company and that she was having a splendid time. Perez had grown up in a very traditional family on Fair Isle, and he hadn’t been sure how it would work – a lassie with two dads and two step-mums. Would the situation confuse her? What would her school friends make of it? Would there be teasing, or even worse?

  But now, it seemed, the blended family was the norm. Cassie would have two celebrations – she’d be back on Orkney for Hogmanay, and they’d celebrate their Christmas then – and two lots of presents. Her only sadness was that she was missing James.

  Once the boy was in bed, Perez and Willow started talking about the investigation, catching up over a late meal. Everything seemed easier when they were together: the complicated family, throwing together a dinner, wrapping presents for James. Perez loved that about Willow, the lack of drama. In the rest of the country, people would be panicking about the trivia of Christmas, but Willow just said she’d pop into Asda in Dounby the next day to pick up what they needed. There were only the three of them, and the shops would be open again on Boxing Day. Nothing to get fraught about.

  ‘Are you saying that Nat confided to George Riley that he’d pushed his father off the North Ronaldsay pier, then regretted it and needed to shut him up?’

  ‘Well,’ Perez laughed. ‘If you put it like that, it doesn’t sound very plausible.’

  ‘It doesn’t explain Archie’s death either. Or the story stones. Besides, we know that Nat wasn’t on any of the ferries the day George was killed.’ Willow was enjoying the conversation. Perez could tell. Pulling holes in his theories.

  ‘He could have got off on a plane. Or one of his fishing friends could have dropped him in Kirkwall. It was a still day. There were lots of creel boats on the water.’

  ‘He wouldn’t have had a car then though. How could he have got to Maeshowe?’

  ‘Public transport? Taxi? A lift with a mate?’

  It was Willow’s turn to laugh. ‘You’re clutching at straws. Because you haven’t tracked down Johnson or his wife.’

  ‘Maybe, but I’ll talk to a few people in North Ronaldsay. Look at any report on the accident.’ He set down his fork and changed tack. ‘Do you think Barbara could have killed Riley? Would she have been sufficiently strong?’

  Willow sat for a moment in silence, quite serious now. ‘I think so. I never gave her enough attention. To me, she was just the professor’s wife. Ridiculously I’d assumed that our perpetrator must be a man. I should know better. I dismissed her as being loud and silly, and it never occurred to me that she could be the killer.’ There was another long pause. ‘I think she could be strong enough. She’s tall and gives the impression of someone who looks after themselves. She cares about her image. Hair professionally dyed, even her outdoor clothes high-end. I can imagine her in the gym, working out, doing resistance training, running.’

  ‘And from what you’ve told me, Johnson is weak and self-important enough to allow her to kill for him. He has that sense of entitlement.’

  The meal was finished, and Perez cleared the plates into the kitchen. He returned with a mug of herbal tea for Willow. She was curled, cat-like, large and sleepy, on the sofa next to the fire. She seemed to be dozing and to wake up again when he came back into the room.

  ‘I think James and I will have a little run out after we’ve done the Asda shop,’ she said. ‘It’ll get him out of the house, and he’ll be high as a kite.’

  ‘What are you thinking?’

  ‘If the weather stays good, and there’s room on the plane, I might take a day trip to North Ronaldsay.’

  ‘Are you sure you’re okay to fly?’

  ‘Sure,’ she said. ‘These small planes, it’s no more dangerous than taking a bus.’

  He nodded. ‘So, you think Nat Wilkinson might be involved after all? After dismissing all my theories?’ He sat beside her, stroked her hair away from her face. For this brief moment, he didn’t care about the case at all.

  ‘Ah, Jimmy,’ she said, ‘it’s a loose end and a bit of a mystery, and you know how I hate loose ends.’

  Chapter Thirty

  PEREZ’S PHONE WOKE THEM BOTH. IT felt to Willow that she’d only just dropped off – sleep came hard to her too in these late days of pregnancy – but when she looked at the clock it was six in the morning. She could only hear Perez’s end of the conversation, but worked out that it was the duty officer at the police station. Perez’s voice was tight, and the questions clipped, so she couldn’t tell exactly what had happened, only that the matter was urgent.

  She got out of bed and went to the kitchen to make coffee. It was clear that Perez would need to leave soon.

  When he joined her, he was already dressed.

  ‘No need for us to continue with the search for the Johnsons.’ His hands were cupped round a favourite coffee mug, blue ceramic, decorated with puffins. Earlier, she’d thought about putting the drink into a travel cup for him to take away, but she’d wanted to keep him here for a few minutes to find out what was happening.

  ‘They’ve been found?’

  ‘Johnson has. No sign of Barbara or the car.’

  ‘Where did they find him?’

  ‘In the middle of the Stones of Stenness. Some crazy runner training for an ultra race out before work saw him in the light of his head torch.’

  Willow knew exactly what would come next, but didn’t jump in. Let Perez pass on the news in his own way. He turned to her. ‘We were too late. He’s dead.’

  ‘How?’ She realized that she was repeating exactly the same questions in the same way as Perez had on the phone.