“It looks like we’re merging with another river.” He immediately put his finger to his lips and everyone remained quiet. He listened intently, then looked forward again. “Try to move the boat closer to the right bank, not right into it, just closer. And it might be a good idea to have fresh rowers.” George took over and Tom was about to, but saw Alice preparing to move and nodded in deference to her.

Whatever Shen had noticed, Barney had picked up on it too, and without exchanging a word, the two of them were incredibly alert all of a sudden, looking ahead, at the water beside the raft, at the banks, cocking their heads and listening. It was almost as if they were mimicking the dog, and the dog in turn studied their every move.

Tom could see there were more rocks in the river up ahead, and although he was sure a channel would open between them, from here they appeared to form a wall. But there was something more disturbing, in the slightly hazy quality of the air just beyond those rocks—he could just see a strip of the river they were about to join, the vegetation on its far shore, but it was as though he was looking at them through a veil.

Then Alice pointed and said, “It looks like rapids up ahead.”

Shen nodded. “Keep bearing right.” He put a hand on Barney’s shoulder and stood, struggling to keep his balance as he looked ahead. “I don’t think it’s much of a drop at all, but it’s still too much of a risk. I think there’s a little bit of a point where the rivers meet, enough for us to beach.”

He lowered himself back into a kneeling position as Emma said, “But didn’t you say we had to avoid the river’s edge?”

There it was, barely beneath the surface, the unease they’d all had since the caiman attack, the full awareness of how dangerous the river could be.

“Yes. Yes, I did.”

Tom smiled at her. “It’s daylight, and we have the dog. I’m sure we’ll be safe.”

That seemed to reassure her, but Tom figured the real issue would be whether they were able to get to shore. There were no decent landing spots here, and they didn’t want to go ashore too soon anyway, but if they left it too late, they might have no option but to tackle the rapids.

He looked over the side of the boat where the current was visibly faster. He’d already put on his other pants, but seeing the change in the river, he automatically reached for his boots and put them back on too.

“Keep bearing right if you can,” said Shen.