The production features criminal and financial cases recently cracked by Shanghai police. Since the end of last year, crew members have spent time at the criminal investigation department of the Shanghai Public Security Bureau－usually referred to as 803 by the public－and branches of the bureau in 16 districts and counties of the city, recording the process of police tackling various cases, including communication fraud, drug trafficking and homicide.

"The series shows the reality. We just worked as a faithful recorder. We started recording even when we didn't know the nature of a case, or who was involved in the case, and worked with the police to detail how they solved it," says Shao Yingli, a general director of the production.

Cai Zheng, also a general director of the series, says: "People are generally curious about police work. Moreover, we want to spread knowledge about the law to the public."

The first two seasons focused on the daily work of grassroots police officers, including solving disputes, patrolling streets and providing services and advice to the public. But this season pays particular attention to police officers who solve criminal cases.