The documentary The Sinking of the Lisbon Maru highlights a largely overlooked chapter of World War II: courageous Chinese fishermen rescued drowning British prisoners of war. Since its screening, the film has moved audiences at home and abroad. It is set to premiere in Britain officially in March. In this episode of PD Studio, director Fang Li, who dedicated a decade to uncovering this piece of history, shares behind-the-scenes stories with us. (Produced by Liang Peiyu, Zhan Huilan, Chu Chu and interns Ying Zhe and Li Xiuchang)