Something launches itself out of the bottle-green river, traces a silver arc in the air, and slaps back down with a report like a rifle shot. Whatever it is, it’s big. The locals waiting with us at the crumbling cement dock don’t even look up.

Sábalo, a man says. Tarpon.

I’ve heard that this fish fights like a prehistoric devil when it’s hooked. Tarpon can grow up to eight feet long and 150 pounds. They swim here in the Rio Frio but are bigger and more plentiful a short boat ride north, on the Rio San Juan, the fluid border between Costa Rica and Nicaragua.

We’re not here for the fish, though we are heading for the San Juan, which runs from Lake Nicaragua, one of the largest freshwater lakes in the world, to the Caribbean Coast. The boat that was to take us there is two hours late. We thought we had all bases covered—we’d either be picked up by the riverside lodge where we’re staying, or we’d take the bote público, which is supposed to run a few times a day. Neither boat has shown.

I’ve had my fill of rental cars and tour operators and realtors. I’m taking a break from a tightly scheduled crisscrossing of Costa Rica, researching the third edition of a guide I wrote about moving here. The last time I did this sweep I thought the new national bird should be the construction crane. This time, the machine’s creak has been silenced by the world economic downturn. Mammoth cranes sit idle on razed hillsides.

Costa Rica was my home for a while; now I’m not sure where home is. I live and work in San Francisco, but part of me feels like I’m waiting for the next big move, the next time I launch myself, like a fish leaping out of the river, into some unfamiliar element.

Meanwhile, I wait. A few boat captains lounge at one end of the cement pier, buying cold soda and plantain chips from a bicycle vendor. One wanders over, his belly hanging out of his T-shirt, and half-heartedly tries to convince us to take his boat to Nicaragua instead of waiting for the public ferry or the lodge’s lancha. He wants more than $100 for the trip; the bote público charges $10.

The day started off deceptively easy with immigration in Los Chiles — it was the fastest I’ve ever left a country. We filled out a short form (the clerk loaned us his pen), got our passports stamped (there was no line), and were on our way to the town muelle (dock). We’ve been waiting here all morning and most of the afternoon.

An aguacero sweeps in—a downpour. Even under a corrugated tin shelter, it feels as if we’re in the eye of the storm. It bounces hard off the cement and onto our legs, and then a sudden wind blows the sheets of rain horizontal. Water floods the slab that is the pier, and we have to move our bags onto a narrow metal bench right on the water. The corroded pole that serves as a backrest barely keeps the bags from toppling into the river.

A young man with copper-colored skin smiles and shrugs. I wonder if he’s Costa Rican or Nicaraguan. Near the border, everyone looks like they’re from the same mestizo stock, but elsewhere in Costa Rica the difference is more pronounced. Costa Ricans tend to be lighter skinned than Nicaraguans, but even if skin tone is identical, Nicaraguans are more likely to be found working the jobs Costa Ricans don’t want: harvesting bananas, doing manual labor on building sites, caring for the kids of two-career households. Nicaragua is to Costa Rica as Mexico is to the U.S. —people from the poorer country stream into the richer one, become a crucial part of that country’s labor force, and often suffer discrimination. Ask any Costa Rican taxi driver why crime is on the rise here, and he’ll have the “answer.” It’s the Nicas, goes the argument, inured to violence by decades of civil strife.

The rain lets up a little. A man peddles by on a bicycle, one hand holding an umbrella. A few minutes later, an old pickup truck with wood plank sides putters by with an oblong box in the back. So much action in so little time! The box in the back of the truck is swaddled in plastic tarps so it’s hard to tell what it is, but I imagine it to be a casket.

Such are the ways we entertain ourselves when there’s nothing to do. With no wi-fi here, I revert to the oldest form of entertainment available—enhancing reality by making up stories about what’s in front of me.

Half an hour later, another diversion rolls up. Two muddy teenage boys hoist themselves out of the back of a pickup full of sheep and make a run for the river, yelling and laughing. They dive in fully clothed, no doubt to rinse off the sheep dung and mud. They scramble back out and, dripping wet, help the driver of the truck load the animals into a lancha. One unhappy sheep gets in a good kick, and when the boat motors off upriver, the truck driver yells, Bon voyage, hijueputa! Have a good trip, you son of a bitch!

When the boat from the lodge finally arrives, it’s laden with a group from the U.S. who’ve been tarpon fishing on the Rio San Juan. We’re catching a ride back to the Esquina del Lago Lodge, but first, the crew will help the returning clients through Costa Rican immigration (easy as pan dulce), get something to eat and have a good long smoke or two.

An hour later, the captain saunters over. “Hay un problemita,” he says. There’s a little problem.

How little? I wonder.

“Hay un difunto,” he says in a low voice. There’s a dead person.

So it was a coffin in the back of the pickup. And it seems the difunto needs to go where we’re going. In our boat.

“No hay problema,” I say. “Pero espero que no tenemos que conversar con el.” No problem. I just hope we don’t have to make conversation with him.

The captain cracks a smile. “Los difuntos son muy serios,” he notes. The dead are so serious.

It’s not quite as funny when they start to load the coffin into the boat. It takes up a whole row—six molded plastic seats and the aisle—at the back of the long and narrow lancha. A young man accompanies the difunto, and the expression on his face looks like something just pierced his chest and he doesn’t know whether to pull it out or leave it there.

We learn that the dead man, the young man’s uncle, was a Nicaraguan who crossed the border to work in Costa Rica, in Puerto Viejo de Sarapiquí. He died of a puñeleado—a knife wound—he suffered in a bar fight. The young man came down to Costa Rica to claim his uncle’s body and to bring him home.

We start up the Rio Frio at dusk. Swallows swoop close to the water, picking off mosquitoes. A flock of parrots flies overhead. Herons and egrets stand sentinel along the river. Howler monkeys contribute their deep-throated call. As we pass under a leafless tree full of black cormorants, it feels as if we’re part of a waterborne funeral procession.

I think fleetingly of rivers and rituals the world over, of the Ganges in India and of the River Styx. But it’s the here-and-nowness of this rite on this river that really hits me. This, I realize, is what I’ve been waiting for: to be smack in the middle of the moment, in the thick of something I could never have predicted or imagined. Streaming up an unfamiliar river with a body in the back of the boat, a body traveling in a closed box that will never open again.

Suddenly the air feels supercharged with oxygen. The last of the day’s light fans out horizontally, illuminating the riverside trees from the inside out. The breeze has dried my rain-soaked blouse, and I catch the scent of some night-blooming flower starting to open. It feels so good to be here, so very good to be alive.

Soon we’ve arrived at the confluence of the Rio Frio, the Rio San Juan, and Lake Nicaragua. The boat noses up to a rickety wooden immigration station right on the water in the town of San Carlos.

There’s no line to enter Nicaragua here, and the only other action is a policewoman in heavy eyeliner and dangling earrings asking the nephew of the dead man for his paperwork. I wonder if they’ve kept the office open late to receive the coffin—the place is all but deserted. A soft breeze, smelling of fish and mud, comes off the water. Out of the corner of my eye I see a short but solid middle-aged woman emerge from the dockside shadows. She pulls the grieving young man to her tightly. He slumps into her, losing several inches in height, finally letting down after single-handedly bringing his uncle home. As we fill out forms in the dim light and pay our $7 apiece entry fee, a tall pale man appears, floating over the heads of the smaller, darker Nicaraguans. It’s the Frenchman who runs Esquina del Lago Lodge. There’s silver stubble on his cheeks, and his blue eyes are kind. “Do you understand what happened?” he says in English softened with French. He’s talking about our fellow passenger, el difunto.

Yes, we assure him. We understand. People die, and they need to be brought home. All we did was share a ride with someone who needed it much more than we did.

I look out over the water. With two rivers and a lake meeting right here, it’s hard to tell which way the current is flowing. But a few wavelets roll towards us, moonlight riding their backs. They gently rock the boat we arrived on, which is maneuvering to another spot along the dock. For the first time I notice its name: The Amen.