At an altitude of 5000 meters in the Himalayas is found Yarsagumba, a caterpillar-fungus that is worth more than its weight in gold. Thousands of Nepalese villagers trek up the mountains every spring, braving difficult temperatures and terrain, in search of this hard-to-find but invaluable commodity. Its trade in Hong Kong and China, where it is considered a medicinal mushroom and elixir of youth, amounts to billions of Euros every year. Watch the journey of this extraordinary creature from mountainsides to pharmacy windows, and the people who hunt it down.

Every spring, tens of thousands of men, women and children leave their villages for a dangerous trek to the high Himalaya to collect Yarsagumbu, a mysterious transmutation between plant and insect. Used in Chinese medicine, it is worth up to 60 000 USD a kilo, more than gold.