However, what surprised him the most was that no one left the team, but pulled through without faltering.

He admits there is a reflection of himself in the characters and the movie is inevitably a projection of his inner values.

"This film stemmed from my passion for adventure and reflections on the relationship between humans and society. It is ultimately a state of mind, not just about nature but how we can better understand and interpret the connection between humans and society through the lens of the natural world," he says.

Yang had multiple near-misses during his traverse of the Changtang region, which has now become a national nature reserve covering a total area of 298,000 square kilometers, making it one of the highest-altitude and largest natural reserves in China.

The reserve has no human inhabitants in its core area and has served as a sanctuary for a unique high-altitude ecosystem and a variety of large, hoofed animals.

In 2017, Changtang, along with the national nature reserves of Hoh Xil in Qinghai province and Altun Mountains in the Xinjiang Uygur autonomous region, jointly issued an announcement prohibiting all organizations or individuals from engaging in unauthorized and illegal crossing activities within the protected areas.

At its worst, Yang didn't get access to water resources in the wilderness.

"I was in an endless expanse of salt marshes with no drinkable water to be found. By the end of the day, my mouth was completely ulcerated, stuck together, and it felt like my throat was closing up, making it hard to breathe," he recalls.

"I began to experience confusion and auditory hallucinations. At night, I worried that I wouldn't be able to open my mouth in the morning, so I used a binder clip to keep it open," he adds.

Fortunately, it snowed later and pulled him back from the brink of death.

However, Yang says that his love for the distant and unknown nature helped him overcome the terrible conditions that he would not have been able to tolerate otherwise and acquire toughness and confidence throughout the journey.

Xiao Han, who works for an outdoor lifestyle media organization in Beijing, says that he was moved after watching the actors shout in triumph on top of the mountain.

"There was huge applause when the film ended," Xiao says, adding that the movie made him realize that travel is a form of self-cultivation, and so is life.

"This is precisely like Journey to the West (a classic novel by Wu Cheng'en during the 16th century) — enduring trials of life and death, obtaining the true scriptures and ultimately achieving enlightenment," Xiao says.

Guo Yingqian, from the Chinese National Geography, says that she feels like the information from the movie is overwhelming and needs follow-up research to fully take it in.

She considers the movie a window to carry people's passion for nature and provide spiritual solace in their journey of self-discovery.

Yang says that the movie presents all relationships for him, encompassing connections between people and between humans and nature.

"Relationships between people are additive, while those between humans and nature are subtractive, requiring a delicate balance," he says.

He points out that the former often dominates daily life, making it essential to deepen one's connection with nature. This connection fosters inner tranquility and harmony, representing a return to one's essence.

Yang emphasizes that cities and wilderness are not opposite, and his movie seeks to portray their intrinsic relationship.

"The journey of four companions venturing deep into the grand canyon is also a process of shutting out the world's complexities. They must not only overcome the harsh natural environment but also break through the barriers within their hearts," he says.

"When all challenges are surmounted, the real test begins: finding and understanding themselves."

Contact the writer at yangfeiyue@chinadaily.com.cn