The sound of heavy rain smacking the canopy above begins long before a single droplet manages to penetrate the dense foliage and touch my skin.
We are making our way on foot through Colombia's Amazon, carving a ragged path through tangled vines, damp leaves and mud, mud, and more mud.
The humidity is a hot, wet sheet clinging to my skin. Our guide Juan, a member of the local Indigenous community, leads the way, a machete swinging from his belt.
When four indigenous children — the eldest aged 13, the youngest barely one — were found alive after 40 days alone in Colombia's Amazon, one question reverberated around the world: How did they do it?
Appeasing the jungle's spiritual owners
"Like all Indigenous people, those children were raised in the jungle with a deep understanding and respect for the jungle and its spirits," Juan says.
From day one, Indigenous science played a critical role not only in their survival, but also in the enormous search operation led by the Indigenous Guard and supported by the Colombian Army.
The search team used chimú, an ancestral medicine, to open the way through the spirits and endure some of the world's toughest conditions.
To appease the jungle's spiritual owners, soldiers made offerings of cigarettes and brandy, sprinkled tobacco on the soil and poured whisky into the rivers. Across the country, elders from Indigenous communities used their sacred medicines to jointly call on the jungle to release the children.
These efforts culminated on the 39th night of the search, when a shaman named El Rubio drank yagé, a sacred psychoactive brew also known as ayahuasca. Emerging from his dream, he told his companions: "I see them."
The children were found the next day.
Jungle salad and pineapple wine
Back on the trek, Juan shows us the myriad ways the jungle nourishes, sustains and heals.
The soft, inner layers of young acai shoots make a delicious addition to jungle salad. The fibrous leaves of the aguaje tree can be shredded and braided to weave skirts, while fruits such as pineapple or choclo, yuca and maiz roots can be fermented to make natural wine.
He stops to point out the roots of the acai palm, which fan out like a purple-red witch's broom. A broth made from combining these roots with coriander is used to treat dengue and malaria.
Juan slices two shallow cuts into the thick bark of a tree. I dip my finger in the wound. The sticky white sap feels like raw latex and tastes slightly sweet. Extract this milk from the side of the tree facing the sun to treat an upset stomach, Juan says. "Take it facing the setting sun, so the sun can draw out the illness."
We gather around a tree so tall that even its roots tower high above us. Bamba trees are used to communicate across distances of up to two kilometres, Juan says. members of the Indigenous Guard used bamba trees to communicate with one another during the search for the lost children.
Swinging a large branch high above his head with both arms, Juan brings it crashing down onto the bamba's massive roots. A deep booming noise rises and reverberates around us, as if from underground lungs.
According to local belief, the Indigenous ancestors and culture originated from a great ancestral anaconda — an embodiment of the life-giving Amazon River system. The anaconda remains a revered creature and Indigenous people are forbidden to attack it with machetes or other tools.
But this doesn't mean Indigenous people must allow themselves to become prey. The trick is to bite the anaconda; the contamination from your teeth and mouth will repel it, Juan says.
Seeing beyond what the normal eye sees
We spend the night in a traditional maloca house with local community leader Adrian Adan and his family.
Seated around a fire, he prepares an Indigenous medicine for us to taste. The tobacco paste is the same substance the Amazon search team used to seek protection from the jungle's spirits. It is shiny and black, with a texture like Vegemite, and eye-wateringly bitter.
Long after everyone has gone to bed, I wander out to use the open-air jungle toilet. As I settle on the makeshift seat I turn off my torch and look up to see a sky brimming with so many stars that, for a moment, I feel like I understand my precise place in the galaxy.
Earlier that evening, Adrian told me that the name of his tribe in his native language loosely translates to "the courtyard of sweet science".
"My ancestors practised science in our way, using knowledge of the jungle and its medicines to see beyond what the normal eye sees," Adrian explained.
Gazing into a night sky like I've never seen before, I believe him.
ABC Everyday in your inbox
Get our newsletter for the best of ABC Everyday each week