The walls were moving, and I didn’t know where my guide was.

I was squatting, pants-down, over a pit toilet within a crudely constructed turquoise shed somewhere around 15,700 feet in the Andean foothills of Peru, trying desperately not to puke. The walls appeared to be having a rave of their own, swaying rhythmically to and fro like one of those inflatable arm waving men you see outside of used car dealerships. Mind you, the walls were not actually alive. They were static, as ordinary outhouse walls tend to be. I was the one collapsing. I was trapped in the psychedelic hellscape that only severe altitude sickness can bring, and I was terrified.

The trouble started early on in the hike, when I was chatting with a charming older man from Australia and suddenly lost all ability to effectively listen to his story. I could piece together 3-4 word strings of phrases, but the broader storyline and purpose of the conversation itself was lost on me. “Would it be ok if we stopped talking for a while?” I asked, confused and trying to be polite.

I sauntered quietly forward along the trail, the wings of my extroversion suddenly and abruptly clipped. “It must just be the cold and a few elevation tingles,” I thought as I shrugged off the encounter.

From the moment we stepped out of the tour bus and onto the impossibly green, rural trail in the foothills of the high Andes, I kept pace with the strongest hikers in our group. I opted not to get a horse when the time came, and charged ahead with two twenty-something girls from the states and the man from Australia.

Once we reached the wooden sign marking the entrance to the Apu Vinicunca National Park, our guide issued us each a permit for day hiking inside the protected area and turned us loose to let us walk at our own pace, presumably planning to meet up with us on the summit. We made our way slowly up the trail as the effects of the altitude began to hungrily grab at our lungs.

The weather quickly took a turn for the worse, as tiny balls of ice began pelting us from out of the sky, the temperature dropping over 10 degrees in what felt like an instant. With no guide in sight, our small group of four donned our heavier jackets and winter gloves and pressed onward in the same general direction of other bloated tourists sitting listless atop their horses.

Once the dizziness and feeling of partial lobotomy set in, I let my fellow trekkers know that I was in a bad place and to keep an eye on me. It began to sleet harder, making our progress slow to a crawl as the once well-maintained trail turned to a soup of mud and ice beneath our feet. Meanwhile, alpacas were casually grazing on high altitude grasses on the next hill over, as though this were any other casual Tuesday. I, on the other hand, couldn’t move my fingers, and mustering the energy to speak in compact, toddler-sized sentences was a laborious effort.

We arrived at the mountain’s saddle with the overlook made famous by so many Instagram selfies just as the sun began to peek out from behind the chilly cloudscape. Our assistant guide suddenly appeared, waiting to take the other hikers down via a more challenging route they had requested. I opted to return back along the normal path, knowing I was fading rapidly and would need to descend quickly. I was on a fast track towards cerebral edema, and now I was hiking alone.

Severe altitude sickness feels like you’re being attacked from within. Like some horrifying mountain spirit has slithered up your spine and wrapped its claws around your brain stem, slowly adding more and more pressure until you surrender and black out. It feels like being shit-faced drunk and fighting to regain consciousness as you make your way back down the mountain without dying. It’s a party I would recommend skipping.

Dizzy in the post-rain blitz, I stumbled and slid as I made my way back towards the bus. The trail became a muck-strewn swamp in parts, and tourists were colliding with one another as they slipped and fell and struggled to stand amidst the quagmire. By the time I reached the halfway point, everyone’s pants were covered in mud.

Still no guide. I wobbled downhill and struggled to stay awake like a college sophomore who’d had one too many cocktails, my mind reeling. There are photos on my iPhone I don’t remember taking. Everything was a challenge, and the landscape felt so impossibly huge, as though I were an unfortunate hobbit about to get trampled on her way to Mordor.

I finally had the good sense to latch onto another, slower group of hikers who were also carefully picking their way through the mud. I told them about my predicament, and we stumbled our way down the mountain together, ragged and wet and dirty by the time we got back to the parking lot.

Nauseous and totally spent, I began frantically looking for my bus or some sign of anyone I recognized from my group.

I located the blue tour bus we arrived in and waddled down its hallway, ready to slump into my chair. It took everything in my power to not throw up in my own lap the entire, winding 3-hour ride home.

I should have acclimatized more. I should have listened to my friends who warned me, and I should have turned around when I felt things start to go sideways. But, sometimes you want to hold your hand over the flame and watch until it burns. To push the red button over and over again. To jump off a cliff into the water and see if you’ll survive. The morbid curiosity of pushing your body right up to the edge can be tantalizing and addictive for a certain kind of person. I’m just lucky I made it out OK.