He found Henderson in Port Control, drinking a mug of tea and listening to Bobby Robertson, who worked for the vessel traffic service. There was a panoramic view over the water and the place looked just like the bridge of a ship, with radar screens and high-tech equipment that beeped and flashed. Sandy was intimidated by the instruments and the sense of efficient expertise, by the smartness of Henderson in his officer’s uniform. The pilot was middle-aged, grey-haired.

‘What’s this about, Sandy? I don’t have long.’ The pilot looked at his watch. ‘I’m just about to go out on a job.’

Sandy thought he was an intelligent man and he shouldn’t have needed to ask. He’d have heard about Markham’s murder. ‘Just a word,’ he said. ‘And maybe somewhere in private?’ He could sense that Bobby Robertson was listening to every word, and he was a famous gossip.

‘Just come along here then.’ Henderson led him away from the control room and pushed open the door to a small bedroom. ‘This is where I stay when I’m on night shift.’

‘You’ll have guessed what this is about,’ Sandy said.

‘Jerry Markham.’

‘Aye, did you know him?’

Henderson nodded slowly. ‘Not well, but I’d seen him around. Once or twice at the Ravenswick Hotel when he was still working for the Shetland Times.’

‘You didn’t like him?’ Henderson had closed the bedroom door and Sandy felt trapped in the tiny space. He’d never liked being shut in. Was this what it felt like to be in a submarine? A prison cell? He was aware of his own breathing and wondered if Henderson could hear it too.

‘I didn’t like his column in the Shetland Times. It always seemed kind of unpleasant to me. Sneering and cynical. He made out he was better than anyone else. More cool. Those of us who loved living in the islands weren’t worth bothering with.’

‘And he’d been Evie’s boyfriend,’ Sandy said.

Henderson looked at him. His eyes were blue and sharp.

‘What are you saying?’

‘That there’d be no love lost between you. Nothing more than that.’

Henderson leaned towards Sandy. Not a threat, but preparing for a declaration. ‘Markham treated her badly,’ he said, ‘but if he’d done the decent thing and stood by Evie when he got her pregnant, she wouldn’t be engaged to me. And she’s the best thing that’s ever happened in my life since my wife Agnes died. I still wake up in the morning and thank God for sending her to me. I have no reason to kill him.’

Sandy wasn’t quite sure how to respond to that. ‘How long have you been on your own?’