‘Are you sure emotion isn’t getting in the way here, Jimmy? Guilt, perhaps, because you didn’t do a proper search of Setter when you had the chance?’

‘I believe both women were killed,’ he said. ‘I just can’t prove it yet.’

‘I can’t dither over a decision for much longer,’ she said.

‘No.’

‘How long do you need?’ Dithering was bad for a politician’s reputation, but so was making the wrong call on a suspicious death. She set her cup carefully on its saucer. ‘How long do you need, Jimmy? I can’t keep the case open indefinitely.’

‘Somebody knows what’s been going on there,’ he said. ‘Not just the murderer. In one of the houses in Whalsay a friend or a relative is keeping a secret. It’s that sort of place.’

‘So, how long, Jimmy? I really can’t give you more than a few days.’

‘I hope,’ he said, ‘that’s all I need.’

‘You have a suspect in mind?’

He nodded but he didn’t speak. She looked at him with curiosity but didn’t press the point. At this stage she didn’t want to know.

‘If I don’t have something by the end of next week, we call Hattie’s death as suicide. I can’t turn it into an accident, however kind that would be for her mother. Then we can get through the inquest and release the girl’s body back to her family.’

He nodded again, but he was already preoccupied. He needed proof. He didn’t have time for long conversations, for allowing the truth to emerge over time. He worked well that way, was much more patient than the Fiscal. But now he’d have to make things happen. He had to precipitate a crisis. He wasn’t sure how he could do that without putting other Whalsay folk at risk.

On his way home he stopped at the Co-op for food, but walking down the aisles he was still thinking of the case. The case and Fran, who was always with him.

The problem with the Whalsay investigation was that so much was going on there. It was hard to unpick the actual causes and connections. Like Fair Isle knitting, he thought. Four different coloured threads, tangled together in the working to make a pattern. It was difficult to follow the line of each yarn, to decide how much impact each colour had on the overall effect.

In the house, he poured a glass of wine, fried a salmon steak quickly on each side, drained spinach and potatoes. Shit, he thought, I forgot to buy a lemon.

He’d finished the meal without really tasting it when there was a knock on his door. He put his plate to soak in the sink before going to answer it. Walking down the hall there was a moment of excitement when he imagined that perhaps Fran had come home a few days early. Would he find her there, standing in the street, looking up at his window, stamping her feet impatiently, waiting for him to answer? He pictured her wrapped in her jacket against the drizzle, the blue scarf with the silver threads tied at her throat. But it wasn’t Fran. It was Sandy, leaning against the frame, obviously drunk and desperate to talk. Perez stood aside to let him in.

He was apologetic in the snivelling way that drunks are – if they don’t become violent. ‘I’m sorry, Jimmy, I’ve let you down. But I couldn’t stand it there, I had to get out.’ After that he became incoherent. He was red in the face and his nose was running. Perez sat him in the living room and made him coffee.

‘Where have you been?’ Perez’s immediate fear was that Sandy had been shooting his mouth off in a bar in town, telling all the world about events in Whalsay. It was only eight o’clock. When had he started drinking?

‘In The Lounge with a few of the boys.’ He must have been sufficiently aware to see the alarm in Perez’s face. ‘But I didn’t talk about the case, Jimmy. I wouldn’t do that!’ He slurped the coffee, pulled a face as he burned his tongue. ‘I just made out I was fed up being stuck out there with my folks, that I was glad to be back in town. You can’t blame me for having a few drinks.’

‘What’s happened at home?’ Because something must have happened, Perez could tell that. Sandy had been calm enough when he’d got back after the trip to London. He’d done well there. He’d proved the Fiscal wrong.

Sandy set down his mug and put his head in his hands. ‘I don’t know,’ he said. ‘I don’t know what’s going on.’

‘What time did you leave Whalsay?’ Perez thought if he kept to the facts, Sandy might drop the drama and come up with a rational explanation.

‘This afternoon. I had a pint in the Pier House and I knew I wouldn’t be able to stop at the one drink. You know how it is sometimes. I couldn’t get pissed in there. Davy Henderson was coming into Lerwick so I got a lift down with him. I phoned up a few of the boys.’ He looked up at Perez, belligerent and defensive at the same time. ‘I’m on leave. I can do what I like.’

‘Do your parents know where you are?’

‘I haven’t told them.’

‘For Christ’s sake, man, there’ve been two deaths on the island. They’ll be frantic. Give them a ring and at least let them know you’re safe.’

‘Mother will have been on the phone to Cedric, trying to track me down. He’ll have told her I went out on the ferry.’ He was sulky as a child.

‘That’s not good enough and you know it.’

‘Look, I don’t care! This is all their fault.’

Perez looked at him. Earlier in the week he’d thought Sandy had matured. The man had dealt with Gwen James with sensitivity, come back with more information about Hattie than Perez had expected. Now he was like a toddler throwing a tantrum over a lost toy, blaming his parents for his misery.

Sandy met his eye. He must have realized how disappointed Perez felt because his tone changed. ‘OK, I’ll phone them.’

Perez carried the coffee cups into the kitchen. Through the wall he heard Sandy’s muffled voice, still defensive and angry, but he couldn’t make out the words. When he returned to the room the conversation was over. He drew the curtains and waited for Sandy to speak. That was why the man was here, after all. Why else would he have turned up on the doorstep in such a state?

‘My parents are going to sell Setter,’ Sandy said.

Perez nodded. ‘It makes sense. They wouldn’t want to leave the house standing empty, and doesn’t Joseph work most of the croft anyway?’

‘You don’t understand. My father doesn’t want to sell. He hates the idea. He didn’t even want the dig to go ahead. And now there’s this grand do in the hall. Mother says it’s about showing folk the coins found on the land, but it’ll be about persuading the Trust to buy the house. If the sale goes ahead, they’ll be digging up all over the land, maybe even knocking down Mima’s house to put up some sort of replica. And my father just says, “Fine, go ahead.”’

‘What are you worried about, Sandy? I don’t really see the problem. It’s your parents’ house now. Their decision.’

‘I want to know why he changed his mind.’ It came out as a shout, so loud that Perez thought the neighbours would hear through the wall. ‘He’s not a man to change his mind.’

Perez sat still and waited for the rest.

‘Someone’s put pressure on him,’ Sandy said. His voice was quieter but still intense.

‘Your mother, maybe. She’s a woman used to getting her own way. Nothing sinister in that. You know how excited she is about the history.’

‘Not my mother. She’s all bluster and talk, but he takes the decisions in the house.’

‘What then?’

‘Blackmail,’ Sandy said. ‘I wondered if that could be it. He needs the money to pay someone off.’ He looked at Perez, desperate to be told that it was a crazy idea. He was Sandy Wilson and he got everything wrong.

But Perez didn’t speak for a moment. He was considering the possibility seriously. The scenario he’d dreamed up to explain the Whalsay deaths didn’t involve blackmail, but perhaps it could fit in with the facts. At this point anything was possible.

‘What might Joseph have done that he could be blackmailed? You’re not saying he killed Mima?’