徵道南、肖北這對高中時代桌球隊風雲人物「南陽北風」，在遭逢一場校園黑道鬥毆意外後失聯多年。 幾年後，肖北領軍數名脫離黑道的年輕人經營工業風理容院，而徵道南帶著黑道繼父老大死後的未解之謎出獄。兩人再度相逢，攜手合作，為阻止黑道即將興起的一場腥風血雨偵查、推敲、解謎，在拼湊一片片拼圖後，終於手握傳說能左右江湖大局的秘密帳簿。 最終，在面對復仇、復興父業、重回黑道，與過著清白自在的平淡人生間，他們做出了屬於自己的重要抉擇。

ZHENG Dao-nan and Xiao Bei, a pair of well-renowned high school table tennis players nicknamed “Nan-yang and Bei-feng,” lost connections with each other after encountering a gang-brawling incident. Many years later, Xiao Bei led several young ex-gangster to run an industrial-style barber shop. At the same time, ZHENG was released from prison with the mystery of the death of his stepfather, the Mafia Don. The two reunite and work to stop a burring storm in the mafia. After investigating, deducting, and piecing the puzzles together, they finally get hold of the secret ledger that can reshape the landscape of the criminal underworld. In the end, they each have to make their own choices of either getting revenge, reviving their father’s business, returning to the mafia, or living a simple life as ordinary citizens.