CAPTAIN MANUEL GARCIA sped the boat around the point, dropped anchor in the W-shaped bay, and cut the engine. Two beaches lay before us, divided by a rocky point. I named the eastern one, which would become my home, Two-Liter Beach, for the bounty of flotsam—mainly plastic bottles—that had washed up. hese were abrasive beaches, covered in small rocks and broken coral, not the soft, relaxing kinds usually paired with paradise.

The interior was no friendlier. Nispero trees, some centuries-old and over 100 feet tall, crowned the landscape, and below them ran a tangle of vines, branches, and other hardwood. Deadfall covered the ground, and a thin stand of palms buffered the shoreline. "The big problem on Isla Pargo is the chitras," Garcia said, referring to the island's sand flies. He and other locals had warned me to bring bug spray, counsel I had flouted. "All the time it's chitras, chitras," Garcia said. As he spoke I realized this was the last conversation I'd be having for a long time. I jumped off the boat and waded to shore. Garcia fired up the engine and disappeared.

Then I cut down a tree.

This served no immediate utilitarian purpose; it just felt good and I wanted to begin with a triumph, no matter how small and meaningless. It was 9:30 in the morning, and for the first time in my life I had to consider where I'd find my next sip of water.

The day before, while scouting Pargo with Garcia, I'd discovered there was no running water—a surprise, given that he'd seen running water two weeks earlier. The Panamanian summer was quickly sucking the island dry, leaving just a large swamp on the north side and two small and stagnant pools on the south. The water had to be coming from somewhere, so I'd shoveled a two-foot-deep well. Brown water had seeped in. It didn't look like anything I'd want to drink, but it came straight from the ground, so I figured it was pure. I'd filled the hole in before I left and reexcavated it with a digging stick during my first hours on the island.

The rest of the day was spent working on fire. Aside from fuel, there are five elements necessary for a bow-drill fire: bow, string, drill, fireboard, and bearing block. I found my bow immediately, and it was perfect: dead but not brittle, and two and a half feet of the most beautiful arc this side of the Roman aqueducts. My shoelace took care of the string. Two branches served as drill and fireboard. For the bearing block, which holds the drill in place, I used a broken coconut shell. The bowstring wraps around the drill with the whittled point pressed into the fireboard. As the drill spins, the friction creates smoke and, theoretically, an ember. But six hours of fruitless toil later all I had was six blisters.

It would be dark soon, so I gathered logs of bamboo drift to make a raised bed frame, and then covered it with palm fronds. I had worked hard all day and felt good. A twinge of loneliness hit, and I thought of my last human contact. Garcia. Shit. The chitras.

In the sand fly, God has created a creature that doesn't sleep. During the day I couldn't sit still for 30 seconds without being swarmed. This made meals challenging, and in an exasperating piece of consumptive symmetry, they bit my face while I chewed. But the nights were truly horrific. The sand flies flew up my nose and into my mouth; they launched repeated expeditions down my ear canal.

On day three, when I left my first scheduled message for Mary, I sheepishly asked her to have my resort support team drop some bug spray on the other side of the island for me to pick up. Later, my pregnant sister would call me a sissy. But she wasn't there, man. She wasn't there.

This wasn't the first time the island had tormented me. Though Panama was in its four-month dry season, the night before I'd awakened to the deceptively pleasant pitter-patter of rain. Stumbling through the black jungle in search of cover, soon I could no longer see my bed. I was lost within 200 feet of my wet nest. Jogging along the beach to keep warm, all I could do was laugh and wait for dawn.

I decided to devote a day to building a lean-to, chopping down small trees for the frame and covering the slanted roof with a heap of coconut fronds. It wouldn't have been out of place in a garbage dump. I called her Monticello. With water, food, and shelter, I needed just one more thing: fire.