At last I got up and ran through my usual checklist. I spun the wheels on the trolley and inspected its side plates for signs of friction. I examined the cable and cable clamps. Finally I started downhill again, to where a smaller platform marked the end of the zipline. Here I checked the brake, the stop block, the emergency arrest device and the tree pads, tightening a few nuts and bolts while I was at it.

I knew the veterans could be trusted. I knew they would test the equipment and use it properly. All the same, I felt a niggling sense of dread every time the zipline was used, because I was ultimately responsible. The buck stopped with me. If anything went wrong, I would be as much to blame as Shaun Steiger.

That’s why I had to suppress a wince when I reached the end of the fire trail and bumped into a loose formation of uniformed campers. The veterans, who were with them, ordered them to step aside. Most of the kids were fizzing with excitement, though some looked less than thrilled. Marcus had been given the heavy bag of ropes. Jake was toting the safety harnesses. They both wore surly expressions as they shuffled out of my way.

‘How’s it going?’ Warren asked me. He was bringing up the rear, where Ali and Aaron, damp with sweat, were dragging their feet.

Aaron stiffened. He was more aware of me now.

‘It’s all good,’ I said. ‘Just keep an eye on those carabiners.’

‘Will do.’

Leaving them, I hurried home, where everything was quiet and peaceful. No veterans were shouting commands. No boys were screeching in the dormitory. The kitchen was a mess; I soon found myself sponging down benchtops, mopping the floor and tidying the fridge. I even had to pick some recyclables out of the compost. But it was calm. Relaxing. Without visitors around, I could hear the distant sigh of surf on the shore.

I’d been on high alert for a whole day, so it was good to let down my guard for a while.

Then I went outside to empty kitchen bins and realised the silence was making my skin crawl. The wind had died down. The birds had stopped cheeping. I stood for a moment, listening hard and scanning the grounds. Nothing moved. The whole place seemed to be holding its breath.

‘Hello?’ My voice sounded feeble. I wasn’t expecting an answer, and I didn’t get one. Yet I felt as if someone was out there, watching.

By the time Shaun and his campers returned, I’d been holed up in my office for three hours, doors locked, blinds drawn.