In the early years of the Republic of China, Xiao Jian was arrested on patrol, a boy who dreamed of becoming the number one detective in Shanghai. During the investigation of a series of mysterious cases, he accidentally touched on their so-called control incidents. He became a member of the Special Investigation Bureau inexplicably. A series of thrilling, bizarre and suspenseful events took over the code name of "Broken Army" and became an unknown guardian.

SWAT captain Shen Ao joins an anti-narcotics team on a remote island, uncovering a drug ring using drones. When his daughter is kidnapped, he undertakes a solo mission to rescue her and dismantle the operation.