Mr. Kang, a celebrated lawyer known for turning death sentences into acquittals, collapses and seemingly dies. He awakens as Jiang Wen, a man who has been cyberbullied and lost everything after a public breakup. Faced with public scorn and false accusations, he realizes he has traveled back in time to an unlucky man with the same name and appearance.

Jiang Wen, now in Jiang Wen's body, is falsely accused of taking unsolicited pictures of a woman, Wang Qian, on a bus. Despite public outcry and accusations of cyberbullying from his ex-girlfriend's fans, Jiang Wen, leveraging his legal knowledge, demands police investigation and surveillance footage, proving his innocence and exposing Wang Qian's fabricated claims. Wang Qian is ultimately sentenced to three years in prison, which shocks many viewers who had initially sided with her.

Jiang Wen extends his legal fight to those who participated in the cyberbullying, including Wang Qian and Faye Lin's fans. He demonstrates how public figures and their followers can be held accountable for defamation and incitement. His actions lead to apologies and settlements, with the compensation being donated to an anti-internet violence foundation. He also publishes an article detailing legal responsibilities in cyberbullying, which is endorsed by the Supreme Court, solidifying his reputation.

After being fired by his former firm for his controversial methods, Jiang Wen establishes his own 'Hanging Sword Law Firm.' He quickly gains a reputation for his unwavering commitment to justice and attracting a talented paralegal, Lin Yu. His first significant case involves seeking justice for a bullied student, Xiaoyu, whose death was initially ruled a suicide. Jiang Wen and Lin Yu uncover evidence of abuse, leading to a complex legal battle against powerful figures.

Lin Yu infiltrates the school as a trainee teacher and gathers evidence of bullying from Xiaoyu's tormentors. Jiang Wen skillfully uses this evidence, along with a key witness and a surreptitious recording, to expose the bullies' intentions and their roles in Xiaoyu's death. Despite attempts by the defendants and their powerful parents to intimidate and mislead, Jiang Wen secures a conviction for intentional homicide for one of the main perpetrators, sending a strong message about accountability.

Following the high-profile case, Jiang Wen faces attempts at retaliation from the convicted's father but remains resolute. He accepts an offer to become a legal counselor for the Tianhong Group, a company known for ethical business practices, furthering his reach in fighting injustice. His dedication to justice, often placing him in the public eye, is consistently affirmed by his actions. Meanwhile, his personal life with Lin Yu blossoms, leading to marriage, where he emphasizes the firm's core values: law and justice are always the bottom line.