Broadband connected immediately. I ran through the messages quickly, deleting the spam that had got through the filter. Nothing from my agent or from the scriptwriter, who was as eager as I for the television project to proceed. As always, there were a couple of messages from readers, who’d reached me through my website. I reply to all these, even to the people who are shocked by my books and write to complain. I have a standard response: you know what’s coming from the jacket and the first page; nobody makes you read on. In fact the first letter was very positive and just contained a query about the publication date of the next book.

The final, unread message was entitled Killer of the North. This is the name of my latest novel. It’s set in Gateshead on the River Tyne, and the title is a play on words. There’s a famous piece of public art there called the Angel of the North, a giant sculpture that embraces visitors who approach the town by road or rail. I was expecting a review – either thanks for a tight and pacey story that kept the reader guessing until the final page or a rant about ‘gratuitous violence’. But the message was very short and to the point: Go home. You’re not welcome here.

No signature and no way to guess the identity of the writer. The address was [email protected]. Simeon was the name of the central character of Killer of the North and certainly not sufficiently common to be the real first name of anyone living here. Most islanders have signed up to shetnet broadband. Even if I were to ask a computer geek to track down the machine from which it was sent, I’d guess it would be from an Internet cafe or the library in Lerwick. I felt as shaky as when my hire car had skidded on ice. My visit was secret. That was the deal. I’d created an alias for the car hire and the flight. Highly illegal, but during the course of my researches I’d come across people who could create a forged driving licence that would satisfy the cursory glances of officials checking in passengers for internal flights. I’d gone to considerable lengths to cover my tracks, but I should have realized that secrecy would be impossible here. Shetland is a place where gossip flourishes. I reached out for the wine behind me and poured a large glass. Soon the bottle was empty.

I’ve never been a good sleeper, and that night it must have been the early hours of the morning before my mind stopped fizzing. In summer it would long since have been light. That summer of ten years before was golden – there were weeks of unbroken sunshine, and the low-lying meadows close to my home were yellow with flag iris and marsh marigolds. Pictures of that time clicked into my head as I finally fell asleep.

I woke to a violent banging on the door. My heart was speeding as I pulled on a sweater and climbed down the ladder. The empty bottle and the remains of my makeshift meal were still on the table. John Sinclair was standing there. He’d been a teacher before he took the post as Arts Trust director. I’d known him well in those days – he’d taught me English – and he hadn’t changed much. Same round belly. His nickname at school had been teddy bear. Certainly he’d changed less than I had, it seemed, because he did a double-take.