Marking Zhang's first foray into the espionage genre, Cliff Walkers-set in the Japanese-occupied puppet state of "Manchukuo" during the War of Resistance Against Japanese Aggression (1931-45)-follows four Soviet Union-trained Chinese agents attempting to sneak into Harbin, the capital of Heilongjiang province, to rescue an escapee from a camp where the Japanese are conducting lethal experiments on prisoners.

During his recent interviews with the popular video platforms Bilibili and Douyin, Zhang says he has always been interested in stepping into new genres, as he believes the Chinese film industry needs to expand its variety of movies to match its massive market scale.

Despite spy films being a popular genre in world cinema, China's silver screens have, in contrast, generally depended on action blockbusters or comedies.