"The Substitute: The Underworld" tells the story of a pair of twins who were separated since childhood and were involved in the whirlpool of the underworld due to a trick of fate.
His elder brother Lin Chen is the ruthless young master of the underworld family "Liefeng Hall". He was seriously injured and hospitalized after a vendetta ambush. He unexpectedly reunited with his younger brother Lin Yuan who was hospitalized due to a cold. In order to stabilize the turbulent court, Lin Chen forced the gentle Lin Yuan to act as his substitute and return to the headquarters to take charge of the overall situation.
Lin Yuan, who had no experience in the underworld, used gentleness and wisdom different from his brother's to make his way in the crisis-ridden power field step by step: he conquered the beautiful killer Bingren, won the sincerity of his brother's fiancée-intelligence officer Qin Yue, and even recruited Brother Hu, the second-in-charge of the rival Green Snake Gang, under his command. He established six major halls, including Shadow, Eagle Eye, and Law Enforcement, to promote the Gale Hall.
