We stop for the night on an island in the center of the river. It’s just exposed grass and mud, with a grove of what look like mangrove trees. A danger light starts flashing in my mind—the island is inhabited! Several canoes lie side by side on the mud beach, just above the waterline. As we draw closer, I see that they’re not canoes but giant black caimans, watching our slow approach with hungry, reddish yellow eyes.

I don’t really want to hop out of our canoe with the caimans so close, but when the chief jumps into the chest-deep water I reluctantly follow his lead. Soon we’re pulling our dugouts up the slippery bank, barely fifty feet from the latter-day dinosaurs.

“Won’t they mind us intruding on their turf?” I ask Ernesto as we walk back to help with the other canoes. “How can we get a good night’s sleep knowing they may decide to use us for a midnight snack?”

“Don’t worry. Caimans are smart,” our leader assures me. “They never take risks. They’ll hear our voices, see our fire, and leave us alone. But since they’re on the island, nothing else will come too close.”

Using caimans as our personal security system seems like a dangerous plan, but this is not my world.

The sun touches the treetops, and the Amazon night starts to put its dark arms around us. The river glows a deep shade of purple-black. With every passing minute the animal-and-insect chorus rises in volume and intensity. Night feeders prepare to hunt. Are those frogs, calling to one another? Could that hungry roar be a jaguar? The one we met before screeched.

The fading light lends urgency to our need to make camp. Ernesto and the chief divide us up and assign tasks. P.J. and I are sent with a group of mostly women and kids to the grove of trees. I soon learn one reason we stopped here. The branches are heavy with a star-shaped fruit that has a slightly bitter taste but is quite edible.

We gather dozens of them. I put on a little juggling act for P.J., and one of the four fruits I have circling from hand to hand falls out of the loop and plunks me on the nose. The impact makes me lose my balance and tumble off a low branch onto the grass. I land gracelessly, on my butt. When I look up, several of the kids are laughing.

I glance over at P.J. and she’s smiling, too. It’s the most natural smile I’ve seen from her thus far.