Synopsis: In the early years of the Republic of China, Luo Shanshan Zhen Xi returned from studying forensic science in Japan and became the first female detective in the patrol room. The most important task for her is to find out the secret of her father's disappearance five years ago. The partner arranged by the police office for Luo Shanshan happened to be the apprentice of his father and the new inspector Liu Fanxi. Luo Shanshan accidentally found a record of his father, which showed that the mastermind behind the broken hand case five years ago was Xu Shaolin, the owner of the Chamber of Commerce, and Fang Zige, the inspector general of the Inspection Department. At this point, new cases of broken hands appeared one after another, and one mystery after another was solved by Luo Shanshan and Liu Fanxi.
"Step by step crisis" takes the surging Shanghai beach in the Republic of China as the whole drama background, and tells a series of suspense stories caused by a serial broken hand case in the 1930s. In the form of unit drama, the drama presents seven unsolved cases, such as broken hand case, family extinction case, secret room murder case, female prisoner case, antique case, opium case and national treasure theft case, which constitute the whole plot, but behind each seemingly different case, there are countless connections buried. Moreover, the drama covers professional knowledge in many fields, such as psychology, medicine, investigation, anti-investigation, etc., and incorporates many industry terms and crime scene simulation pictures.