The series starts with Kate Woodcroft, a prosecutor, leaving court and heading to her office. It’s raining outside, and she comes in all soaked. Her colleague Brian greets her and compliments her on her win in the Butler case. He also informs her about a new case, mentioning it’s a next-level one. She then says goodbye to Brian and enjoys a drink while looking at the rain outside.

Meanwhile, Sophie Whitehouse, the wife of James Whitehouse, a member of parliament, shows up at a party. People greet her and ask her about James, so Sophie tries to call him to remind him about the party but can’t get through. At that moment, James is in his office having a meeting with an older lady to listen to her complaint. The conversation goes well when James decides to help the lady; however, his assistant comes up and whispers something in his ear that completely changes James' expression. James instantly rushes home and texts Sophie to tell her to meet him there as well. Feeling that something is off, Sophie leaves the party immediately, thinking something has happened to the kids.

Sophie and James finally get home, and James immediately admits that he made a big mess this time. They sit down, and James tells Sophie that he’s been having an affair with one of his parliamentary aides, Olivia Lytton. It had been going on for five months, but he stopped it two weeks before the conference. James weakly claims it was just sex; however, Sophie knows there must be a reason he is confessing all this to her right now. It turns out the story is about to break in the news, and that night the chief of communications comes to their house to talk to James about how to handle the situation. Sophie is furious and just wants to protect their children first.

Meanwhile, Kate is alone in the office and starts to read about the new case she received. Chris Clarke, the chief of communications, arrives and reads aloud all the news that has already been released about James' cheating scandal. Sophie is so hurt that she runs to another room. All the happy memories between her, James, and the kids come to her mind, and she can't believe James did that to her. She then can't help but look up the face of Olivia, the woman her husband slept with, and vomits right on the phone screen. In the other room, Chris keeps instructing James on how to dilute the hate that is coming his way. After taking a moment to pull herself together, Sophie walks back to the other room and declares that she will stay with him through this because they have been married for 12 years and have 2 children. James and Chris are happy to hear that, and Chris gets ready to leave while briefing them on what they should do with the press: no elaboration, only admit that James made a mistake, regrets it, and now wants to prioritize his family and his work. At that moment, they realize their daughter Emily has been staying on the stairs and listening to part of their conversation. Sophie brings Emily back to her bedroom while James sends Chris away after Chris sarcastically jokes about James’s affair.

James goes upstairs, and Sophie starts to question him about the details of his affair. She is shocked to learn James slept with Olivia in hotel rooms "20 or 30 times," and she understands it was not just sex. They then go to sleep with their work clothes and makeup on. The next morning, Sophie wakes up, turns on the TV, and watches James' public declaration about his affair. She later goes to pick up her kids from school and feels awkward around other parents, but she tries her best to keep her cool.

Meanwhile, Tom, the Prime Minister, heads into James' office. James reassures the PM that this is the first and last time he has made a big mistake in his marriage. Tom also agrees to the amendments James wants to introduce to the immigration bill. Tom then leaves after reminding James to pay more attention to Sophie's public image.

At home, Sophie is preparing a quick dinner for Emily when Emily asks a question about a university club named Libertines, a club that James and Tom were members of during their time at Oxford. Sophie then recalls her time at Oxford when she first met James. That night, she was drinking with her colleagues, Alison and Holly, when she caught the look of James from the other side of the room.

In the present, both James and Sophie are trying to act like nothing happened to maintain their image of a perfect family and a highly respected politician. Meanwhile, Kate keeps working late overnight at her office on a high-profile case. Her only entertainment is sometimes calling her friend Alison to have a quick chat before returning to work.

The next morning, James sets up a lunch date at the Parliament building with Sophie. Sophie can't hold it in anymore and tells him that she will stay with him, but she isn't willing to act like nothing happened in public to polish his image. Sophie mentions that her mom forgave her dad for cheating on her and she doesn’t want to make the same mistake. James apologizes to her and tells Sophie that he wants to fix his mistake and is willing to do whatever it takes, even giving up his career and resigning. Sophie is moved by these words and lets him hold her hand. In the car on the way home, Sophie recalls the memory of when she and James were dating. James was the perfect guy that everyone wanted. He had everything a girl could dream of, and at that moment, Sophie already knew they would get married.

In her office, Kate flips through the pages of the case file and discovers that the "high profile" case is actually related to James and Olivia’s affair. Kate gasps when she realizes how serious the case is.

Meanwhile, on his way out the door, James is stopped by two detectives. They’ve been trying to contact him regarding Olivia and an allegation of rape. It is a metaphorical blow to James as he hears the news.