New narrative angles are also explored in the documentary. From the perspective of Evans Carlson, a US Marine Corps general officer, and Joseph Stilwell, a US Army general, the bravery and exceptional contribution of the CPC-led Eighth Route Army in the war is highlighted. Their positive remarks also helped former US president Franklin Roosevelt to have a relatively objective view of the CPC, Xia says.

"From their viewpoint as a third party on the War of Resistance Against Japanese Aggression and CPC-led anti-Japanese base, we can better understand the real opinions of US diplomats and military personnel toward the Party at that time," Xia says. "It can also benefit diplomatic work today."

A picture of an unyielding nation was unrolled before these foreign eyes. In the second season of Shanhe Suiyue, the strong spirit of Chinese revolutionaries are reflected not only through their bravery on the battlefields across the nation, but also through their morale in pursuing economic development and expectation for a bright future.

For this production, it was not an easy task to search for the necessary historical references among the hoards of files and documents available, let alone the tight schedule and the fact there was no room for the slightest error.

"This production is like a document, and thus is highly demanding in its authenticity," Xia says. "Watching this kind of rigidly produced documentary, people often treat it as a record of history. If we mistakenly use one file or picture, people will doubt its credibility.

"But we also need to pursue artistic aesthetics," he continues. "So when we tell stories in this documentary, the focus is not put on the 'stories', per se, but the people. With these people, history will become relatable."

Xia says a major challenge in making this production was that firsthand film footage of the Party during wartime is scarce.