Business tycoon Li Mingyuan, to fulfill a dying friend's final entrustment, protects his daughter Chen Yuwei for eight years. When Yuwei suffers severe physical and mental trauma from malicious bullying by wealthy girl Zhou Ting's gang, Li Mingyuan launches a revenge, destroying the bullies' family through business means, but encounters a counterattack by a power group led by Zhao Qiming. When the threat escalates to Yuwei's life safety, Li Mingyuan awakens the underworld force hidden for thirty years, "Old Gun". When past rules and present power collide head-on, he will make everyone who extended a dark hand pay an unbearable price.