"Sure," I say, with absolutely no knowledge of what's in store for me. I had taken mushrooms containing the psychedelic drug psilocybin before, and had enjoyed the experience enough to rate it as easily one of the top five experiences of my life. So this ayahuasca stuff would be a piece of cake, right? Well, no.

That night at the house of the shaman and his family, Marcelo calls several other backpackers and I into a small room where we would finally drink a short glass of the extremely bitter tea. What we find in the room is like nothing we expect: A medicine man at least 70 years old is sitting on a chair before us smoking a cigarette. A feather is stuck through his nose and he's wearing a loin-cloth. Only a loin-cloth.

As we sit in a half-circle on the floor before him, he asks us questions to try to ensure that we're ready-- spiritually and physically-- to drink the tea. "You have fasted for twenty-four hours?" he asks in Spanish. "Wait, wha?!" I think. No, I hadn't done that. In fact, my stomach was about as full as I could ever remember it. (Let's just say the bathroom facilities in the Ecuadorian jungle are not up to my usual standards.)

But I'd come this far. "Sí," I tell him. "No comida para mi."

He pulls a three-liter plastic bottle out from under his chair, sets it on the ground in front of him, and begins reciting sing-songy incantations while blessing the bottle's contents with the smoke from his cigarette. (Of course, it's anyone's guess exactly how much of this ceremony is really traditional and how much is performed only to look authentic for tourists.)

Soon he's pouring glasses of the ayahuasca tea for each of us, and he delivers them to us one at a time. I'm the last one to drink, so I already know by everyone else's reactions that the tea is not going to be very good. But the tea's disgustingly bitter taste can't even live up to my already lowered expectations. It's virtually unpalatable, which, considering the mind-altering effects it's about to bring on, is probably for the best.

We sit and wait for twenty minutes after drinking the tea before anything happens. Then the backpacker to the far left of me stands up, leans his head out the window, and vomits. It's okay, the shaman assures us, that's what's supposed to happen. Then, like that contagious-throwing-up scene from Stand by Me, the guy next to him vomits. Then the person next to me does. Unfortunately, because of my stuffed-to-the-gills stomach, I never do.

What happens then? Well, let me offer an extended excerpt from what I wrote in my journal the next day. The opening sentence, I assure you, is no exaggeration:

"That was the worst night of my life. I will, as always, blame someone else. Our guide Marcelo apparently thought we'd be okay without fasting before the ayahuasca. Turns out, all the food in my stomach absorbed the nasty tea, and instead of puking twenty minutes in-- like we were supposed to-- and returning to Earth three hours later, I writhed in agony for nine hours....

"It shouldn't go unmentioned, however, that I did manage to enjoy some of the positive effects of the ayahuasca: colorful open-eyed hallucinations, extreme visual mind-f***s, and an all-together giddy demeanor. But then, somehow, things began to turn south, or perhaps a better way to put it is that things turned into hell on Earth. It's difficult to describe with any precision, but I'll give it a go anyway. I began losing track of who I was; I couldn't form abstract thoughts; I turned into an animal looking only for survival...

"I couldn't wake up from the nightmare, couldn't return to anything resembling a functional human being. I had roughly a hundred false awakenings. They lasted forever... Never in my life have I felt so utterly alone, so helpless, so out of control, so insane. I remember asking a biologist from West Texas, as I was finally coming out of the daze, to tell me his life story so that I could latch on to someone else's coherent thoughts. So I could remember where I was, what I was doing.

"The most frightening part was not knowing if I'd ever return to normal. I imagined myself-- or rather, I would have imagined myself if I remembered how to imagine-- like Jack Nicholson at the end of Cuckoo's Nest when they wheel him in: the lights are on but nobody's home. It entered my mind that maybe I was dead, and that if I wasn't, maybe I wanted to be."

So, if you couldn't pick up on my subtlety, this was not a very positive experience. Don't mistake this post for an anti-drug cautionary tale, however, since my fellow backpackers mostly had very good times.

I realize now that I was stupid in not fasting for 24 hours before taking this very powerful substance. I've learned-- and earned-- my lesson.