I felt my neck prickle. It seemed to fit. But why? Why would Derek Jameson kill his twin? Anger at Bob’s dishonesty? At his corrupt behavior? Revenge for something that had happened when they were children? Revenge was a dish best served cold but forty-odd years was practically frozen solid. And it seemed that Bob was the leopard who never changed his spots. He had been consistently dishonest all his life. Had something happened lately between them? Something that tipped the balance? The final straw?

I tried to focus on the view, to clear my head and see if anything slipped into place without being forced. Something was moving in the distance, something tiny, like a fly moving up a wall. It took me a few minutes to realize it wasn’t a car but a cyclist. I took out my phone, turned on the camera, and zoomed in, enlarging the view. It was Derek, negotiating one of the hairpin bends. Not wearing a helmet. He must have taken his bike from the truck as it traveled through Glendara. I watched him for a minute, my mind replaying the conversations I’d had with him over the past few days.

What possible motive could he have had for killing his twin? Derek’s wife had dementia; she was in residential care. I presumed it was one of the Jameson Grace Homes. Was it something to do with that? Had he found out about the conditions in the homes? I tried to imagine how it would feel to discover that your brother was responsible for ill-treating someone you loved. Derek seemed kind. I pictured his expression again when he’d spoken to Mary in the hospital. He had spoken so gently to her. And then suddenly it hit me.

I remembered what Derek had said that day at the waterfall, about having feelings for someone else, someone other than his wife. He’d said he felt guilty about it. I’d thought at first it was Sue, after I’d witnessed their encounter in the alley. But he was just making an effort with her, as her uncle.

Could it have been Mary he’d been talking about? His brother’s lover? Mary had said she’d had offers but no one compared to Bob. Was it possible Derek had been one of those offers? Bob had never been to Inishowen before but what if Derek had? Had Derek decided to kill Bob here, on purpose? Where he could comfort Mary afterwards and pick up the pieces?

I looked down again at Derek and watched him tackling a serious climb. Amanda was right about one thing. It was difficult to believe he had only one leg. I called the Garda Station.