Barney worked on building a stretcher for Nick, using the frames of backpacks, and despite the limited space, the others were keen to help. Even when there was nothing they could do, they watched him working, fascinated by his progress.

An hour in, and sensing that darkness would fall soon, Alice divided up the remaining snacks and they ate. Tom shared his with the dog again and so did the others in his boat.

For the first time since leaving the riverbank, Joel spoke. “Our last food and you’re giving it to the dog.”

No one responded, except by making a more visible fuss over the dog. Alice smiled at him and said, “We haven’t even given you a name, have we? What can we call him? Tom, what do you think?”

“Something Spanish, I guess.”

Emma said, “What’s Spanish for dog?”

No one answered, and then Joel said, “Perro.”

He sounded so grudging that Tom almost laughed and stopped himself only by repeating the word. “Perro.”

Immediately, the dog’s ears pricked up and he looked at Tom, and everyone else laughed. For a few minutes, people took turns calling him that most basic of Spanish names, and so he officially became Perro.

They rowed on, and after another half hour, the jungle seemed to become heightened in some way, as if in anticipation, and then darkness fell with its usual speed, enveloping them and reducing the world to nothing but the rafts they were sitting in.

They didn’t know how much life was left in each of the remaining flashlights, so they decided to use one at a time, with someone just behind the two rowers, moving the light from side to side. The beam rarely reached the dense cover of the jungle, so they had only the reassurance of the water all around them.

It was impossible to hear their progress. The noise of the jungle and the gentle splashing of the oars in the water were constant and uniform, producing the illusion that they were simply suspended in the night.

Those who weren’t rowing or holding the light slept on and off. Tom didn’t. He took a shift with the flashlight, then took over one of the oars, and kept at it for a few hours, the concentration and the building muscle fatigue helping to take his mind of his hunger. He couldn’t even remember now when he had last slept.

Finally he heard someone move behind him, and Sandeep’s voice came out of the dark, saying quietly, “Tom, let me take over. You’ve been at it for hours.”

“I’m fine,” said Tom.

“Even so, get some sleep. Let me do this.”

Tom handed him the oar, then felt his way blindly to where Sandeep had been sitting.