Li Pengfei has guarded relics of the ancient kingdom of Loulan in China’s western Xinjiang Uygur autonomous region for 12 years, charged with the task of keeping would-be tomb raiders away from what was once an important oasis city along the Silk Road. Li and his small team also face a huge personal challenge – enduring months of discomfort and loneliness with no mobile phone signals, limited water and few interactions with other humans.