Kang Yeo-joo is a best-selling writer. She only writes crime stories, dealing with cruel murder cases. She constantly thinks about how to murder people for her novels. Kang Yeo-Joo is married to Han Woo-sung. He is a lawyer, specializing in divorce. He wrote a memo to his wife stating "If I cheat, I die."
Kang Yeo Joo, the famous crime novelist, spends her day locked up working on her new novel. However, her publisher needs her at her book concert. Knowing they'd show at the house, she makes a quick getaway to her neighborhood convenience store. Meanwhile, her husband, divorce lawyer Han Woo Sung, appears on all the networks and gets in the public's spotlight as the perfect husband. Later, Woo Sung steps out of a studio apartment after meeting with one of the female TV program hosts.
Yeo Joo reminds Woo Sung of her power over him and the Disclaimer of Physical Rights that got her to marry him. However, she now loves him enough to kill him. Baek Soo Jung, one of Woo Sung's very close acquaintances, doesn't show up for her morning show causing her manager to look for Detective Jang Seung Chul. Meanwhile, Soo Ho applies to become Yeo Joo's assistant, and Woo Sung prepares for his entrance into politics.
The detectives continue investigating Baek Soo Jung's disappearance at the studio apartment, but they find it rather difficult getting their hands on the CCTV footage. Later, the investigation into Soo Jung's disappearance gets official underway. And because of it, one person tries to find the truth behind it, and another frantically moves to keep it covered up. Meanwhile, Soo Ho finds blood in Yeo Joo's basement.
Woo Sung falls victim to blackmail and needs to come up with 50,000 dollars by tomorrow or risks having the CCTV footage of him entering Baek Soo Jung's studio apartment leak. However, he comes up with a plan with only 5,000 dollars in hand. Meanwhile, Yeo Joo continues to tag along with the detectives and leads them to find Soo Jung's trophy that could possibly be a murder weapon.
Woo Sung gets taken to the hospital after almost drowning in the Han River. Yeo Joo races over to the hospital to see him after hearing about the accident and sees a person she didn't ever expect to see there. Meanwhile, Soo Ho and a senior of his begin a secret mission to uncover the truth that Mr. Ma is trying to hide, while a floating body is discovered in the Han River. Later, Woo Sung's blackmailer suddenly appears and threatens Woo Sung again.
Although the police have Yeo Joo as a suspect, she plays it cool and believes that they can't pin anything on her without a motive. However, little does she know, the police have Woo Sung on camera entering Baek Soo Jung's studio apartment. Later, Woo Sung decides to tell Yeo Joo about his affair with Soo Jung, and his blackmailer collapses when he realizes he doesn't have the footage of Woo Sung anymore.
The detectives rush to the hospital, where an informant lies in the emergency room, claiming to know who killed Baek Soo Jung. As they uncover new facts about her murder, the investigation takes a new turn. Meanwhile, Yeo Joo takes her publishers out for a team dinner and shocks everyone with the contents of her new novel. Later, Woo Sung seeks help from Mr. Nam regarding the investigation.
Yeo Joo starts to sense that Woo Sung is having an affair and goes to extremes to confirm it after finding a suspicious hair on his shirt. Later, Woo Sung finds himself mixed up with someone he never intended to see after taking on a new case. Meanwhile, Soo Ho asks his seniors, who had kept an eye on Yeo Joo, the reason behind it as the mystery surrounding her grows darker.
Yeo Joo doesn't give up on piecing together Woo Sung's affair and visits Seoyeon University, where she thinks it all started. Soo Ho gets a surprise visit from an agent who once watched over Yeo Joo. He learns an interesting fact about her that raises an eyebrow. Meanwhile, Woo Sung goes to Baek Soo Jung's funeral and meets Yoon Hyung Sook, the CEO of Soo Jung's entertainment agency.
Yeo Joo walks out calmly from Woo Sung's office after seeing Mi Rae hiding in the bottom cabinet. However, she forewarns him of the topic to come up later at dinner. Baek Soo Jung's manager manages to escape and tells the detectives what he knows. Meanwhile, Yeo Joo orders Soo Ho to find out who sent her the letter without a return address. Later, with Baek Soo Jung's manager's testimony, the detectives come knocking on Yeo Joo's door.
Yeo Joo meets with Mr. Ma, and their past gets revealed. However, Yeo Joo still doesn't know what Mr. Ma's true identity is and why he is keen on getting a publishing deal with her new book. Meanwhile, Soo Ho listens in on their conversation, and Yeo Joo's current publisher freaks out after her friendly reminder of what happened nine years ago backfires. Later, Baek Soo Jung's manager changes his story and throws the detectives into the dark.
Although Woo Sung denies having anything to do with Mi Rae, the young university student, Yeo Joo keeps a close eye on his whereabouts. Woo Sung finds Mi Rae at the police station and helps her out. Meanwhile, Soo Ho tracks down Yeo Joo's past that leads him to her then-boyfriend, who happened to have died in a mysterious car explosion. Later, Woo Sung finds out that when Yeo Joo got taken in by the police, she wasn't going in as a testifier.
Woo Sung gets arrested for Baek Soo Jung's manager's sudden death and is put in a holding cell. At the same time, Yeo Joo becomes preoccupied with a questionable proposition. Meanwhile, Mi Rae falls into despair because of her mother and something shockingly unexpected. Later, in the middle of the night, Woo Sung sneaks out to retrieve the flash drive.
Yeo Joo and Woo Sung arrive at the cemetery after the sun sets in an eerie atmosphere. Woo Sung finds it strange that she brought him here without knowing her true intentions. However, after getting everything ready, Yeo Joo and Woo Sung enter the cemetery. Later, Woo Sung remembers Mi Rae and calls her just in time, and Assemblyman Park tries to figure out what Mr. Nam's intentions are supporting Woo Sung in the election.
Woo Sung is confused after seeing Yeo Joo lie about not knowing Baek Soo Jung’s perfume. He tells Jin Ho his suspicions about his wife. However, his speculations about her escalate as Jin Ho reveals what he knows. Meanwhile, the detectives think they can gain a crucial clue in the case and reluctantly head to Yeo Joo’s house. Later, Yeo Joo explains her deductions regarding the murder and shocks the detectives.
Surprisingly, Ms. Yeom confesses that she was the one who murdered Baek Soo Jung. However, Yeo Joo knows the truth and advises the detectives otherwise. Later, Mi Rae shows up at Woo Sung's office, telling him she wants to divorce her husband with assets reaching 200 million dollars. Meanwhile, Woo Sung frets over what Yeo Joo knows.
