Former "Netherworld" mercenary leader Li Mu faked his death three years ago and went undercover as the security captain of Yulongwan Residential Area, only wanting a peaceful life. Su Wanqing, president of the Su Group, was coerced by her family. Li Mu repeatedly stepped in to help, repelling hoodlums, rescuing people in an elevator, fighting back in the board meeting, and taking on the "Raven" organization head-on. Su Wanqing's feelings for him shifted from employment to deep love, and the two married. As the old case was exposed, the truth behind the destruction of Netherworld pointed directly to close confidants by their side. Joining forces with his wife, Li Mu wiped out Raven and the Tianji Pavilion, rooted out the traitor Shen Xiao, finally attained peace, and co-founded a security company.