‘Hey, do you have a water purification tablet or two I could borrow?’ he asked. ‘Think I’m all out.’

Tim stared at him for a couple of seconds and then nodded.

‘Yeah, I think I might have some back in my bag,’ he said. ‘It’s just up there on the path.’

‘Don’t you purify the water you get from the stream?’

‘Yeah, but I was just going to do it all in one go when I got back to camp.’

‘Ah, got you.’ Tom paused. ‘Are your bottles and your CamelBak all back by your bag too, then?’

Tim stared at him, then gave a sharp nod.

‘I thought I saw you filling something else up when I was coming over,’ Tom said carefully. ‘You were bending down by the stream and you had something in your hands.’

Tim continued to stare at Tom, his expression unreadable. After a few seconds, that glassy smile returned.

‘I was just splashing some water on my face,’ he said. ‘Trying to get some of the sweat and dirt off, you know?’

Tom nodded. He stared out across the stream, listening to its gentle lapping and burbling. He could hear the wind, faintly, but it was muted down here. He looked back at Tim.

‘No,’ he said.

‘Huh?’

‘No, you weren’t washing your face,’ Tom said. ‘It’s dry.’

Tim’s mouth opened, then closed again. His eyes never left Tom’s face. After a moment Tom grinned.

‘Come on man, what’s the big secret? You can tell me.’

Tim said nothing. He continued staring at Tom, and his right hand moved in his coat pocket. He shook his head slowly back and forth.

Tom took a step towards him.

He hadn’t meant it to be threatening – at least he didn’t think so; he had no plan in his head when he started moving – but Tim flinched and took a step back, raising both hands in front of him. As he did so a small object went tumbling from his coat pocket onto the grass between them.

Tom paused and looked down, then bent to pick it up.

‘That’s… that’s not…’ spluttered Tim. ‘That’s just mine.’

Tom stared at the watch in his hand. It was bulky and black; one of those digital ones with two metal buttons on either side of the face. For a second he felt only confusion, but then a sudden realisation hit him and the feeling in his stomach went from a background gnawing to a horrible, wave-like lurch.

The watch was Gary’s.

Tom turned it over in his hand, held it close to his face, and saw two small stains on the black strap. Dark maroon splotches. They were faded, almost washed clean by the water, but they were there. Tom felt something hot rising inside him, a sharper version of the angry adrenalin he sometimes felt on the football pitch.