Gisele Beker, a 26-year-old Argentinian, trudged for hours in scorching sun to the sprawling Wirikuta desert, craving peyote, the cactus hallucinogen locals in Mexico deem sacred.
Joined by three Mexican friends, Beker was living her dream as part of a new wave of tourists taking a trip for a "trip" - in this case to see where "lophophora williamsii" takes her.
"Did you strike gold yet?" she asks her Mexican friends anxiously - after a 700-kilometre hitch-hike - as they search the desert floor for the small, spineless cactus full of psychoactive alkaloids, particularly mescaline.
The drug is technically illegal but for centuries it has played a role in indigenous culture in northern Mexico and Texas, where it is part of transcendence and meditation for cultures such as the Wixarika, or Huicholes in Spanish.
So much so, that this remote corner of San Luis Potosi state has become a bit of a promised land for those who have trekked here to try peyote, despite the logistical challenges, since the 1960s.
The tourists just keep trickling in.
They have not been deterred by the difficult topography, and there is no indication they have paid any heed to rusty, metal signs announcing regularly that "HARVESTING AND SELLING PEYOTE IS A FEDERAL CRIME."
Nor has the legal background done anything to change the availability of local guides who, when they hear the magic words from tourists - "We want to go out to the desert" - sidle up and quietly offer their services.
Cesar, one of Gisele's friends who wanted to keep his last name private, recalls his favorite saying: "You do not find peyote. It finds you."
When the group locates what they have come for, the rituals start in earnest.
Typically, people ask permission from the Wirikuta desert where the indigenous people believe the universe was created.
Then an offering is made to the plant and people are careful not to uproot it. The peyote is splashed with water and its small button-shaped fleshy parts are eaten.
"It is like a fruit, fleshy but very bitter," says Gisele.
The native people see the plant as the symbolic heart of the deer god, as well as their communications hotline with the gods.
Every year, the local community treks to Quemado hill led by a shaman who gives blessings and makes offerings to the peyote.
Soaking up the mystical feel of the place, Mexican Eliana bites on her peyote. "It's like going inside your own spirit," she says. "When I finish, I am going to think some more and then I am leaving."
Many people experience heightened senses, synesthesia, vomiting and other effects while on the drug.
Chris Biddle, a 32-year-old South African, said he and his girlfriend felt connected to nature, but that the experience "is not for everybody."
Local expert Jose Luis Bustos, 67, underscored that people trying to treat peyote without respect would perhaps pay a price.
"Peyote is not a drug," he said. "It is a sacred plant. And it must be treated with great respect, because if someone does something bad, the plant just may punish him, treat him badly."
Other locals also have voiced concern at cases of foreigners who came from around the world only to die alone in the desert, or wind up in local psychiatric facilities.
Mayor Hector Moreno warned: "Peyote is exclusively for (indigenous) Huichol culture. The rest of us are only supposed to promote its preservation and respect for it."