This drink will make you sick. It will make you throw up, in huge, violent bursts, and you'll probably need to crawl to the toilet at some point as well.
Then the hallucinations will start. Maybe they'll be pleasant and life-affirming. But the chances are they'll be nightmarish, full of ghouls and demons that will appear from within.
You'll feel weak, maybe like your heart is slowly stopping, or like the world around you is shrinking, escaping from your grasp.
Eventually, however, it will wear off, and you'll find yourself back in the South American jungle, deep in the forest - but you may never be the same again.
The drink I'm talking about is ayahuasca, a hallucinogenic, medicinal shaman brew of the Amazon that has long been used in the indigenous cultures of Colombia and Peru, but is also experiencing a surge in popularity as a tourism attraction for Westerners seeking something different.
The tourists want in. They've heard about this spiritual brew, an infusion of plants containing dimethyltryptamine (DMT), that - depending on your point of view - either heals its users and allows them all new spiritual understanding, or just gets them wasted on hallucinogens.
It's a business. Go to Iquitos in Peru, the nerve centre of ayahuasca tourism, and you'll see signs of the practice all over the place, and will be offered an experience within minutes.
Some of the ayahuasca is brewed and distributed in controlled environments, providing tourists the safest experience possible - while some of it is doled out by shoddy shamans keen to make a tourist buck.
Greg Carter is the director of Chimu Adventures, an Australian travel agent specialising in Latin American adventures.
His company has seen a rise in interest in ayahuasca tourism, which he puts down to travellers looking for that "authentic" experience.
"Originally ayahuasca had a bit of a cult status on the backpacker scene," Greg says.
"Backpackers went to Peru, and with the lure of a natural, legal hallucinogenic drug, people obviously tried it. I suppose in the last few years with the growth in cultural tourism, and experiential tourism, people have moved on to this kind of thing to enhance their experience, become more ingrained in a local culture. People want to do what locals do."
Greg stresses that while it might be popular, ayahuasca is not exactly 100 per cent safe.
"It's something we don't generally sell. There's a lot of danger around it, and a lot of people do die every year. Quite often that goes unreported. There are some places in Peru that are recommended, or who do have a good reputation - places like Rainforest Expeditions - but there's a lot of random shamans in places like Cusco that if you walk off the street and give them 20 bucks, you can get ayahuasca done without any preparation. There needs to be a fasting and cleansing period leading up to it. I would say to people, be very, very careful."
I haven't tried ayahuasca. I'm interested in it, but I'm also scared of it. It sounds like a massive risk. An Australian friend of mine, Chrisy Long, however, has spent the last month at an ayahuasca retreat in Peru called The Way Inn.
The experience has had such a huge effect on her life that she's quit her job back home and decided to stay and work at the retreat.
"Ayahuasca is an incredible medicine," Chrisy says. "While I don't think the majority of people will suddenly leave their jobs, for me, it just feels right. I've had my spiritual awakening and now the universe is really pushing me in that direction."
Right. So what's the big appeal? "You can talk to as many people about their experience and they will all be different. Everyone is on their own personal journey. Everyone has different experiences.
"It's really difficult to put non-linear experiences into linear words. Aya just works so differently with everyone. You either get amazing fractal geometric visions and an acknowledgement of outer space, or you get experiences that are more family- or relationship-based, working with childhood or past-life experiences.
"You go through different family members, as many as seven generations before and ahead, all the emotions you went though and all the sad and happy memories, and you begin to understand your purpose as well as their purpose in life. It's like having 20 years of therapy."
Sounds... weird. Rather than focus on the one crazed hallucinogenic experience, The Way Inn does nine-day ayahuasca sessions with its clients.
"We're focused on clearing those lifelong blockages, helping to undo lifelong patterns which you can take back with you into the Western world," Chrisy says. "We find the majority of clients transform in some way for the positive by the end of the retreat."
Like I said, I'm interested in ayahuasca, but I'm also scared of it.
Our Western view, the one that's hammered into us from school age, is that "drugs are bad, mmkay", but who's to say that's true in this case?
What if the shamans have got it all figured out? What if ayahuasca is a path to spiritual nirvana?
Or, on the other hand, what if it's just a night of petrifying hallucinations and soiling yourself? I doubt I'll ever have the guts to find out.
Have you ever tried ayahuasca? Would you? Have you had an experience overseas that could match ayahuasca? Are you surprised that this has become a tourist attraction? Have you engaged in risky behaviour while travelling? What was your experience like?
- FFX Aus