Lu Chenyuan, a top international agent and medical officer who was once code-named "Yan Luo", was exhausted physically and mentally after a bloody mission that resulted in the sacrifice of his comrade Su Beichen three years ago. He chose to hide in a corner of the city and became an ordinary clinic doctor, using his medical skills to atone for his sins and longing for ordinary. However, a blood-stained old contract was handed to him by a pale and determined woman. She is Su Beichen's sister, Su Wanqing.
Su Wanqing used to be a talented girl from a prestigious school, but she worked as a full-time housewife for Ai Gan. After seven years of hard work, what she got in exchange was the betrayal of her husband Chen Yuxuan and the wealthy daughter Lin Weiwei. He caught her in bed, transferred her property, exposed her illegitimate child, and slandered her as mentally ill. Overnight, she lost everything and even nearly lost custody of her child. Standing on the ruins of life, the extreme pain unexpectedly "awakened" her hidden potential - photographic memory and meticulous logical analysis. She recalled the vague mention of "Dr. Lu" and a promise her brother had made during his lifetime.
Su Wanqing's arrival tore open the past that Lu Chenyuan had tried to bury. The guilt and commitment to his comrades made him unable to refuse. The two form a revenge alliance: she provides information and revenge targets, and he provides protection and the power to break the situation. Lu Chenyuan has a silver needle in his left hand to save lives and heal the wounded, and an iron fist in his right hand to punish evildoers. He helped Su Wanqing collect evidence, learn business and legal knowledge, and regain her property step by step. At the same time, they met Gu Yanche, an elite lawyer who seemed cynical but actually had an extraordinary background. Gu Yanche initially came into contact with the case due to family interests, but was attracted by Su Wanqing's tenacity and Lu Chenyuan's mystery, and was voluntarily involved in this dangerous game.
