In 1930s Shanghai, gangsters hold sway, foreigners lay traps, and spies lurk in the shadows. Crime runs rampant amid the glittering streets of the foreign concessions. Zhong Lang, the "Tiger Detective" of the police station, was once brought low by a wrongful call in a murder case. With the help of Han Fei, a sharp young investigator, and Yu Shengnan, a medical professor skilled in forensics and criminal investigation, he rebuilds the detective unit. From the return of the "Throat-Cutter" killer to a sniper mystery behind a gang shootout, from a black-gun conspiracy at an arms factory to a Japanese spy's assassination plot, they navigate the foreign concessions' open and hidden attacks and the city's blood-red fog. With courage, they break through deadlocks; with skill, they hunt down criminals. In a dark age, they seek the truth for the innocent and wield the sword of justice.
