Set in the mid-1920s. A resourceful young police officer named Qiao Chu Sheng is on the trail of a brutal but devious killer. Realizing that the police force will need some extra help with this difficult case, he decides to form an elite crime-busting detective team. He reaches out to a young man who has recently returned from studying in Great Britain, Lu Yao. Qiao Chu Sheng has learned that Lu Yao has remarkable powers of deduction and a brilliant mind – and believes he can help crack this difficult case. To round off the team, he enlists the help of Bai You Ning, a focused young female reporter for a daily newspaper. A free-thinking, independent young woman, she has a strong sense of justice – and pledges to help catch the killer. The trio form a small detective squad that specializes in solving strange and unsettling murder mysteries.