On the eve of World Environment Day, we launch a three-part special series on the restoration of Xinjiang's Gurbantunggut Desert. First: Life in the Sand — deep in the Kalamaili Nature Reserve, where the Przewalski's horse, last true wild horses on Earth are returning. After nearly four decades of collaboration between researchers and engineers, our reporter Shang Jianglong tells the new desert story of return, resilience, and hope.