Espionage, justice, state security officers, plain appearances, foreign agencies — plot twists abound in popular series, Xu Fan reports.

When director Qi Dao was conducting research for his espionage series The Silent Storm, he was surprised to discover that the recruitment process of the Ministry of State Security was quite different from what he imagined.

For those unsung heroes fighting on a secret battlefield to defend the country's safety, they are required to have ordinary appearances to avoid being noticed by the public.

"I previously thought they recruited talents who had good combat skills. It was interesting to hear that they have rigorous appearance requirements, with consideration for the facial features, like the proportions of the eyes, nose and mouth, to ensure a plain and simple look, aiming to be the least impressive in a crowd," Qi tells China Daily during a recent interview.

With extensive research involving insider interviews and collecting reports on China's efforts to crack down on spying, Qi has brought to life the nerve-wracking espionage world of the eponymous novel written by Lai Ji, a prolific writer and teacher at Southwest University of Political Science and Law in Chongqing.

Qi recalls that he stumbled upon Lai and was recommended to read the novel in April 2022. After becoming engrossed in plot twists, the director, who is also a die-hard fan of spy tales, decided to adapt the novel into a drama, spending two and a half years to produce it.

The 16-episode series has been broadcast on China Central Television's CCTV-8 and streamed on Tencent Video since Nov 7, garnering over 42 million views on related topics on the popular social media platform Sina Weibo.

Set in the fictional city of Binhai in 2019, the drama begins with a national security police investigation of a spy case. An engineer is involved in stealing confidential aerospace data under the orders of a foreign spy agency.

As the investigation unfolds, it is revealed that a former national security police officer, who left the force in 2000 after accidentally causing a suspect's death, is connected to the case. This revelation sets the stage for a poignant journey that follows how the dedicated police officer spends 19 years, primarily working undercover in several gang rings, in his quest to clear his name and chase the top agent of the agency.

Liao Fan, the first Chinese mainland actor to win a Silver Bear for Best Actor at the 64th Berlin International Film Festival, takes the lead to portray police officer Wu Yu, a solitary hero unwavering in his convictions.