David hands Jake an immunity agreement as Scandal Season 4 Episode 18 begins. He wants Jake to testify against B-613. Jake refuses saying signing an immunity agreement is signing his own death warrant. David tells Jake he can't protect him unless Jake agrees to testify. Jake still refuses.
Charlie, Huck, and Quinn go looking for more agents to recruit to testify against B-613 and Jake. They find three, all of whom they hope will help them make their case and convince Jake to take the immunity deal. Jake listens in on a bug he placed in David's office.
Olivia wakes up with Russell who tells her she shouts in her sleep in at least six languages. He reveals that he knows her true identity and she gets a phone call. A congressman needs her help getting his father off of death row. Complicating the issue is the fact that his father confessed to the murder.
Lizzie North meets with Mellie's sister, Harmony. She knows Harmony could spell trouble for Mellie's campaign and advises Mellie to bring her into the family to keep her under wraps.
Olivia meets with the congressman's father. He tells her he's not innocent and that he wants his son to live his life. She believes he didn't commit murder and says she's taking his case. Huck, Quinn, and Charlie get the agents to the safe house when Quinn gets a call from Olivia about the George Reed case. They leave Charlie in charge.
Cyrus visits Abby to warn her about Harmony being in town. He knows Harmony's visit will cause a wave of petty jealousy to overtake Mellie which will in turn cause Fitz to pull his support for her political aspirations. Harmony shows up in sky high heels and a bright red dress and Mellie takes her on a tour of the White House. Abby calls Olivia to tell her about Harmony's arrival and ask about the George Reed case.
Huck and Quinn discover Dan Hoffman, the math teacher George Reed supposedly killed, slept with at least three more students, with the number likely higher because of his frequent job hopping giving motive to more mothers and fathers as well as his ex-wife. Olivia goes to interview her only to find out she died three weeks before.
Charlie returns from a supply run to find two of the spies he was supposed to be watching dead and the third seriously injured. Jake enters the room wiping his hands and they begin to fight. Jake ends up killing the third spy before ducking out of the apartment.
Fitz refuses to have dinner with Mellie and Harmony telling her to do it herself. He tells Cyrus Mellie needs to toughen up if she's ever going to make it through a campaign, much less survive the pressures of being in office.
David learns Jake killed their witnesses and Charlie tells Huck and Quinn Jake has to die. Quinn disagrees but Huck agrees saying Jake isn't Jake anymore. He's gone into survival mode and needs to be put down.
Olivia calls Quinn to tell her that Lisa Hoffman died of pancreatic cancer. She sends Quinn and Huck to look through her things for evidence that she was the one who killed her husband. In the basement, Quinn finds a gun matching the make and model of the one used to kill Dan Hoffman. While Quinn and Huck watch the cops enter the home to find the gun, Huck tracks down Jake's position.
Fitz attends the dinner with Mellie and Harmony. She and Fitz talk about her soapmaking ventures while Mellie plasters a smile on her face and waits for an opportunity to change the subject. She and Harmony begin arguing and Fitz has to shut their conversation down. Harmony threatens to use the information she has about Mellie against her big sister if Mellie doesn't start respecting her.
Huck and Quinn find Jake in Liv's building. They believe Olivia might be in danger and rush over to try and rescue her. Fitz finds Mellie nursing her wounds in a glass of hooch. He advises Mellie to apologize and make it right. She's hurt that Fitz couldn't act the part of the supportive partner at their dinner while she played the candidate.
Quinn and Huck interrupt Olivia and Russell only to find Jake across the hall. He threatens Olivia's life should anything happen to him. The next morning Charlie brings Huck and Quinn coffee. They're joined by David at the Washington Mall. The three spies agree Jake has to die but David wants to tell Olivia the truth about what they're doing. David argues that Olivia will not like their decision.
Fitz asks to meet with Harmony in the Oval to smooth things over between her and Mellie. He tells her that Mellie is jealous of her half-sister and the fact that their father left her mother to raise Harmony and marry Harmony's mother. Cyrus overhears Fitz tell Mellie she's going to win this race and he's going to be beside her when she does.
Olivia meets with George Reed and his son and tells them that the ballistics report on the gun found in Lisa Hoffman's home matches that of the gun which killed her husband 15 years prior. But the gun was too well cared for to have been there for so long. Olivia accuses the congressman of being the one to pull the trigger and framing Lisa Hoffman posthumously for her husband's murder in order to free his father.
Sitting in his office, David has a flashback to the night Jake killed James Novak and spared his life. David calls Huck to tell him that he will testify in his own case against B-613 since he watched Jake kill three people. Jake overhears everything.
Olivia tells George Reed that Nick needs him. She will be there to him to help restore his reputation when he gets out of prison. George Reed agrees and Nick Reed is taken into custody.
Huck waits for Olivia outside the courthouse and tells her he's there to protect her from Jake. Jake watches as David walks his assistant to her car in the parking garage of the justice department building. Jake tells David to take two steps to his left and Holly, his assistant, was B-613. Olivia tells Huck that she knew what Jake was doing the whole time. Jake tells David he's always been in.