The fragments of clinker here were sharp, with razorlike edges that scored lines in Kane’s shoes and the palms of his hands when he stumbled. What a final journey to make. How did you choose which antenna to hang yourself from? Seeing it every day, perhaps, sensing a significance that slowly revealed itself. When do you think “That’s the one”?

There it was: one of the towers supporting the high-frequency arrays. Kane approached over the rough ground, touched the metal to gauge its temperature. Then he found the first of the footholds and began to climb.

The strut from which Rory’s noose had been attached was high—six or seven meters off the ground. It would have been a long drop, a sharp break. Kane hauled himself up, then sat on the crosspiece and tried to think through the logistics. Balancing while tying it, your hands occupied. Is the noose already around your neck? Secure the cable, slip off. No one around. There’d been no other cars since Kane had arrived here. You could spend an hour getting ready. But equally you could spend an hour setting up what looked like a hanging, arranging Rory’s body, and then climbing back down and disappearing into the dreamscape.

If that was what happened, it meant the killer was probably still on the island with Kane now. Which meant they’d be very alert when new people turned up, and willing to go to extreme lengths if they believed they were going to be discovered. Nowhere to flee—it was you or them.

Birds tracked him overhead as he returned to the beach, white ones, fairy terns, curious companions. They hovered, dispersing only when he focused his attention on them. Early accounts of the island described how tame and fearless the birds had been, oblivious to humanity, sitting calmly among the sailors so that the men could just reach out and wring their necks.

Violence infused the place. It seemed to press up from beneath the beauty, to make the whole place a lure, a trap, and the beauty something to poison yourself with. Rory’s hut sat alone, but not alone enough to escape. There was something it hadn’t disclosed yet, Kane felt sure. It looked like it wanted to speak, simultaneously slumlike and idyllic with a couple of plant pots, and a chimney, and three steps up to its painted door.

Kane walked back to the steps and tried lifting the top one first. It was secure. But the middle step was loose and came away when Kane pulled, revealing a cavity below. Inside was the missing box file.

He took it out and opened it. Whatever documents the file had originally contained had been disposed of. It held only loose Polaroids of children and a school exercise book. On the front cover of the book it said: Secret.