After his tale was over, I noticed everyone quietly applying more DEET. I did the same. Then, as night deepened, the sand flies came out—in numbers. Much smaller than mosquitoes, they looked like white motes drifting in the light of the lantern, so small that they made no noise, and you normally don’t feel them biting, unlike mosquitoes. The more the night deepened, the more sand flies collected around us.

Eager to record some of the stories being told, I hurried back to my hammock on the other side of camp to fetch my notebook. My new headlamp was defective, so Juan Carlos loaned me a crank flashlight. I made my way back without difficulty. But on my return, everything looked different in the dark; I halted, hemmed in by dense vegetation, realizing I had somehow veered off my rudimentary trail. The nighttime rainforest was black and alive with noise, the air thick and sweet, the leaves like a wall surrounding me. My flashlight’s feeble beam was fading. I took a minute to frantically crank it up to a greater brightness, and then I played it carefully over the ground, looking for my tracks in the forest litter, or any sign of the trail I’d hacked with my machete earlier in the day.

Thinking I saw tracks, I moved in that direction, walking quickly, pushing aside the undergrowth with a growing sense of relief—only to be blocked by a mammoth tree trunk. I had never seen this tree before. Disoriented, I had stumbled deeper into the jungle. I took a moment to catch my breath and get my heart rate down. I could neither hear my companions nor see the light from where they were gathered. I thought of calling out to them, asking Woody to come get me, but decided not to expose myself as an idiot this early in the expedition. After intently examining the ground and cranking the light up several more times, I finally found my real tracks and retraced them, bent over and peering at the forest floor, each time waiting to advance until I located the next scuffmark or depression. A few minutes later, I spied a freshly cut leaf lying on the ground, its stem oozing sap, and then another. I was back on the trail.

Following the slashed leaves and vines like bread crumbs, I retraced the trail to the center of camp, where I gratefully recognized Juan Carlos’s hammock. Thrilled to be safely back in camp, I circled the hammock, probing the wall of forest with my light for the path that would take me to where the rest of the group was chatting. That would be easy: I could now hear the murmur of voices and see the light of the Coleman lantern peeking through the vegetation.

On my second circle of the hammock, I froze as my beam passed over a huge snake. It was coiled up on the ground, just to one side of Juan Carlos’s hammock, three feet away from where I stood. Impossible to miss, the snake was the opposite of camouflaged: Even in the dim flashlight beam it looked practically aglow, the patterns on its scaly back brilliantly etched against the gloomy night, its eyes two bright points. It was staring at me, in striking position, its head swaying back and forth, its tongue flicking in and out. I had walked right past it—twice. It seemed mesmerized by the flashlight beam, which was already starting to fade. I hastily cranked it back up into brightness.

I backed up slowly until I was out of the snake’s range, which I figured might be more than six feet—some snakes are able to strike their entire body length. I have had many encounters with venomous snakes—I’ve been struck at several times and hit once (a rattler that bounced off the toe of my boot)—but I had never in my life faced a snake like this: so fully aroused, so keenly focused, so disturbingly intelligent. If he decided to come at me, I’d not be able to escape.

“Hey, guys?” I called out, trying to keep my voice steady. “There’s a giant snake here.”

Woody responded, “Get back. But keep the light on it.”

The snake remained motionless, its gleaming eyes fixed on me. The forest had fallen silent. Woody arrived seconds later, with the rest of the group in tow, their headlamp beams swinging wildly through the murk.

“Jesus Christ,” someone said loudly.

Woody said quietly: “Everyone stay back, but keep your torches on him. It’s a fer-de-lance.”

He pulled his machete from its scabbard and, with a few strokes, transformed an adjacent sapling into a seven-foot snake stick, a long pole with a narrow, forked end.

“I’m going to move him.”

He advanced toward the snake and, in a sudden thrusting motion, pinned its body to the ground with the forked end of the stick. The snake exploded into furious action, uncoiling, twisting, thrashing, and striking in every direction, spraying venom. Now we saw just how large it really was. Woody worked the forked stick up its body to its neck as the snake continued to whip about. Its tail was vibrating furiously, making a low humming sound. Keeping the neck pinned with the stick and his left hand, Woody crouched and seized it behind the head with his right hand. The snake’s body, thick as his arm, slammed against his legs, its dazzling snow-white mouth gaping wide, unsheathing inch-and-a-quarter-long fangs that pumped out streams of pale yellow liquid. As its head lashed back and forth, straining to sink its fangs into Woody’s fist, it expelled poison all over the back of his hand, causing his skin to bubble. Woody wrestled the snake to the ground and pinned its squirming body with his knees. He pulled a knife from his belt and with his left hand, never releasing the snake with his right, neatly sliced off the head. He impaled the snake’s head firmly to the ground by driving the knife through it, and only then released the snake. The head, along with its three inches of remaining neck, wiggled and struggled, while the headless snake also began to crawl off, and Woody had to pull it back into the pool of light to prevent its escape into the brush. Through the whole struggle, he never uttered a word. The rest of us had been stunned into silence as well.