Hungry after a long day, Roman asked where he could find food. “The bossiest little girl took me to the house next door and asked the grandmother there to make dinner.” As he waited, three little boys grilled him in Spanish about everything, which, he said, was fun. Over the course of the meal, the entire extended family trickled in. An older brother had spent eight years in the States, so he and Roman traded stories, each practicing their second language on the other.

Roman easily made it up Tajulmuco’s straightforward route to the top, but was disheartened to find the mountain’s forests overgrazed by goats, its trails littered in trash, and the summit views obscured by cloud. He had approached and reached the summit using nothing more than his Spanish language skills in gritty, rural Guatemala. That was the fun part. As parents, Peggy and I admired Roman for this creative approach to travel in the Internet age. He went beyond securing transport, food, and lodging in a foreign land. He relied on his command of a foreign tongue and his ability to interact with strangers to find his way.

Roman was as thrifty abroad as he was at home. Equipped with local knowledge about prices, he bargained before committing to any purchase. “Money talks, loudly, in Guatemala,” he wrote, where budget travel made him less of a target. He traveled for a spell with a British woman whose parents were Scottish, observing that “She is exceptionally stingy. Which is great, because we can practice our Spanish negotiating prices.”

Peggy emailed him about making friends. He described the budget travelers who wanted to do things, but who were too intimidated without a guide and too cheap to hire one. He enjoyed playing the role of trip leader for these newfound friends and described his approach in detail: First, it was important to be friendly: “Hey, let’s go get food.” Next, inclusive: “Hi there, you’ve been here a month, how do I do this, what’s it cost?” Then offer a suggestion: “I hear there’re free salsa lessons tonight, want to go?” or a bit of advice: “Here’s how you climb X on your own, but you might not get as good a view without doing a tour package that leaves earlier because of clouds.” Now, set the hook with an invitation: “Want to go to the hot-springs tomorrow? It’s easy and safe.” Finally, lead them there and escalate: “Hey, the hot-springs were fun, weren’t they? How about climbing a volcano? It has a sacred lake in the crater surrounded by Mayan shrines. No, we won’t need a guide. We can just go there and ask some people.”

It sounded like Roman was far from a lone wolf on a solo adventure. One traveler he met—who wrote us later—remembered how helpful he had been to her:

Roman was always so knowledgeable when he was showing me around or translating for me and I will always remember how cunning and strong he is and all of the valuable lessons he taught me. . . . He took me under his wing and took care of me since I was traveling alone in Guatemala, and as I have told him, I will be forever grateful for crossing paths.

BY MID-MARCH, AFTER he had spent a week or so around Guatemala’s Lake Atitlan, climbing volcanos and visiting hot springs, Roman planned to head for Tikal, the ancient Maya’s most iconic ruin. There he’d talk to people about El Petén, the biggest Latin American wilderness north of Panama and full of Mayan ruins. He identified his next adventure there in northern Guatemala near its borders with Mexico and Belize.

“Dad,” he wrote me in mid-March 2014, “there’s an undeveloped Mayan ruin 63 km into the jungle. Everything I’ve found says get a guide and mules because there’s no freshwater and carrying water that far is impossible.” At eight pounds a gallon and one gallon a day, Roman couldn’t carry much. He’d be too heavy and slow. Apparently five thousand people do the trek a year, so he wasn’t worried about pathfinding without maps: “If I get lost I just turn around and follow my blazes out. What do you think? Hump 12L out and see what drinking swamp water is like? No good, head back?”

I was flattered he asked my opinion and pleased to see his evaluation of the risks. While we had spent months in rainforests in Asia, Australia, and Central America, other than a week-long walk across Corcovado when he was eleven, we had generally stayed at research stations, where we slept in huts or base-camp tents and made day hikes in search of animals and plants.

Our self-propelled camping adventures, where we moved by foot, boat, bike, or ski across a hundred miles or more, had been mostly in temperate, boreal, and arctic landscapes. He could certainly boil water for drinking as we had at the bottom of the Grand Canyon and across cattle lands in Mexico and Australia. Unfortunately, fuel for his Jetboil stove had been difficult to find. But because it was the dry season, he said, fires wouldn’t be “equatorially hard” to start, a nod to his experience with 100 percent humidity and daily afternoon rains at the center of the Earth’s tropical regions on the equator.

Roman admitted that safety from criminals was his biggest concern. Like most of the world’s international borders that are largely wilderness, El Petén has its share of bandits, hostile locals resentful of outsiders, and narcos transporting Colombian cocaine to Mexico. Even tourism could be dangerous. He met one young traveler who had witnessed a “tourism cartel” send armed men with guns to chase down tourists and ensure that they hired the “right” coopertiva guides. Guiding was a big source of cash for the rural economy; nearby narco traffic and access to weapons, apparently, had encouraged its criminality.

He had asked for my advice, so I wrote back. If thousands of people did the trek each year, he wouldn’t really be alone.

I expect that you’d be able to find fresh water—there’s no way to carry enough. I like your walk in with two gallons. If you find none the first night you have enough to walk out. Ideally you find water coming out of limestone cenotes [sinkholes]. If it’s moving and there’s no trash or people around, it’ll be pretty good. Otherwise boil some at night in camp, let it cool and carry it the next day. Boiling swamp water is OK. I am pretty sure you will find water.

My email reminded him about tinadizole, the one-pill treatment for giardia that we would buy in developing countries where giardia and dysentary are common.

I’d say go for it, I wrote in closing.

But two weeks later his plan had changed. Now he described a new route, much longer and far more remote. He’d be gone ten days. He lacked a good map of the area’s “thin jungle trails” and would follow them with little more than a compass and his wits. I shared his apprehension:

I expect I’ll spend a couple days out there, eat a snake, get scared, and turn around. If all else fails, I can always just walk south and hit a road. The distances here are quite small. Honestly, I’m more worried about dealing with the tourism cartel on the mule track from Carmelita to El Mirador than I am of getting lost in the woods.

Roman had designed a tent for his trek, bought material, and had a Guatemalan child sew it together. He looked forward to seeing how his design would work. I’m also pretty excited about getting to use a machete, he wrote. He promised to update me once more before he left and to leave his plans with a local ex-pat in the nearby town of El Remate. But reading and rereading the email describing his new plans, my lips tightened. Ten days? Thin trails? No map?

I OPENED GOOGLE Earth and searched for the place names he’d listed. Uaxactun and El Mirador—both in El Petén—looked far off the “Gringo Trail” of popular tourist destinations. I zoomed in. Flat, featureless forest stretched like a green Berber carpet in every direction. I panned around. Other than a handful of brown patches that looked like wetlands to avoid, there was nothing to help guide a hiker. There were no mountains, no rivers, no pastures, no visible roads or trails. It also looked far from Uaxactun to El Mirador—and empty.

I Googled images of El Petén: flat jungle with ancient Mayan buildings, their steps climbing far above adjacent forest trees. A Wikipedia map confirmed that the northern borderlands of El Petén are desolate. Roman’s planned route was in the center of the largest area of rainforest left in Central America: seven million acres, covering parts of Guatemala, Mexico, and Belize.

I started picking apart his email, composing a response. He needed to know that a map wouldn’t be much help without topography, rivers, or trails. He needed to be reminded to watch out for the most dangerous snakes in the Americas: the fer-de-lance that kills more people than any other and the bushmaster, an aggressive viper that can grow to ten feet long.