Set against the backdrop of two decades of major societal development in China and progress in its law-enforcement methods and capabilities, the critically acclaimed tale earned 8.6 points out of 10 on review aggregator Douban and has won the market, largely, for its in-depth examination of the complexity of humanity.

Zhang Songwen's character Gao appears as a humble fishmonger who relies on his small business to take care of two younger siblings. However, he is bullied for purchasing a comparatively cheap TV set, which fails to satisfy a villain's appetite for blackmail and bribery. After tasting the benefits brought by guanxi, or "a special relationship", Gao is seduced by the lure of the criminal underworld, a dark network that he once hated and fought against.

"In contrast, the police officer An Xin (played by Zhang Yi) is a lonely hero and idealist, who will make you believe that even the darkest corner can be illuminated by a glimmer of light," says Zhu.

With the show's popularity index reaching 11,800 — normally, 8,000 marks the threshold for a hit — on iQiyi, which produces the drama, Dai Ying, the streaming giant's senior vice-president, says that the company believes the drama's success can be attributed to creative writing and the multifaceted characters.

With many viewers spending their Spring Festival holiday following the suspense-filled drama, the finale of the TV series, which was released on Feb 1, sparked heated debate online.

Despite describing the drama as "a shrimplike delicacy", referring to its mediocre beginning and end, but with an excellent middle section, many viewers suggest the show signals the rise in quality of domestic TV offerings and express their hope that more, equally compelling, homegrown series will be forthcoming.