家庭的出身和经历决定了方自力（苗侨伟 饰）日后成为商界枭雄，他做事果敢、心狠手辣，常令同行不寒而栗。但多年的打拼累坏了身体，妻子唐善行（万绮雯 饰）对他悉心照料，无奈冠心病每况愈下。不巧此时他的主治医生猝逝，新接手的姚日山（黄宗泽 饰）面对方自力的不信任不仅没有怨言，反而以德报怨征服自力。日久见人心，正当自力对日山的人品与医术产生感激之时，一场意外夺去了日山的生命。死后的日山把心脏换给了自力，换心后的自力性情开始发生了变化。日山的女友小吉（周丽淇 饰）忍痛处理日山的后事，再处理一起案子期间，她与换心的自力有过几次接触，似乎在他身上发现了日山的影子......

The ruthless Fong Chi-Lik suffers from congestive heart failure, and was fortunate to have the recently died Yiu Yat-San donate his heart to him. After going through heart transplant surgery, Chi-Lik's personality changes drastically; Chi-Lik turns into a good man with a caring attitude. But when Chi-Lik discovers Yat-San's "accidental" death involved him and his wife, he gets lost between love and righteousness, good and evil. Meanwhile, Yat-San's twin brother Yiu Yuet-San returns to Hong Kong to prepare for his brother's funeral and falls in love with his brother's girlfriend Yuen Siu-Kat. The plot thickens when Yuet-San finds out that his twin brother’s death was not an accident and begins investigating to uncover the truth.