The episode begins with Peggy being interrogated by agents Sousa and Thompson at different times. Both men are trying to wear her down while Chief Dooley and the Russian doctor watch from the other side of the glass. Agent Sousa accuses Peggy of being one of Howard Stark's women and Agent Thompson demands to know what is going on. He tells her that it doesn't add up what the evidence is saying and what he witnessed in Russia. She keeps insisting that is because they are looking in the wrong place. Sousa tells her about all of the evidence they have against her and she is telling them that they are wrong and a trained killer is out there.
Jarvis shows up at the SSR and asks Rose to let him in. She plays dumb and insists she doesn't know what he's talking about. He asks her to page Chief Dooley and let him know that he has Howard Stark's signed confession. Peggy is taken into the conference room in handcuffs where Jarvis is waiting with Chief, Thompson and Sousa. They all want to know what is going on. Jarvis tells them that he has Howard's confession and they will receive the signed page that night when Howard arrives. In exchange, Mr. Stark demands Jarvis and Agent Carter's freedom. Dooley says they are to stay put and when Howard arrives with the signed document then they will be free to go but Peggy is fired. Dooley returns to his office where the doctor is waiting and Agent Sousa tells the men on the floor to keep an eye on Carter.
Jarvis informs Peggy that Howard is not coming and that he panicked when she didn't show so he wrote the confession himself. Peggy is furious because of course Howard will not be showing up, but she insists that she isn't mad at Jarvis- just at the situation.
Chief Dooley calls his wife and they make plans to have dinner together. He is hopeful that things will start moving in the right direction with his family again and he'll be able to stay at home again. Dr. Ivchenko continues to stand by the open window and talks to the Chief about his family. He looks outside and sends Morse code signals to Dottie who is across the street. She has just returned from buying a baby carriage. Peggy looks across the room and sees the doctor. She grabs a notepad and writes down what he is saying. She and Jarvis translate the code and realize that it is a timetable and that Leviathan is coming.
To gain back their trust, she tells Chief Dooley, Thompson, and Sousa everything. She tells them the truth about everything that has happened and why she conducted her own investigation. She calls them out on their shoty police work and bad investigation. She reminds them of how narrow minded they have been towards Stark and that is why she had to privately conduct her own investigation. They want to know how it was possible for her to run her own investigation right in front of their eyes without raising any suspicion. She tells them it's because she was invisible to them- that none of them see her unless she's filing,bringing them coffee, or bringing them their lunch. She accuses Dooley of seeing her as an abandoned kitten dropped of on his doorstep that he needs to protect. Thompson of seeing her as nothing more than a secretary. And Sousa of seeing her as a girl on a pedestal with questionable taste in men. She got away with it because she isn't seen. She tells them about Captain America's blood and how she stole it. She reveals that she isn't sure why she did it once she found out what it really was. She thinks that maybe she was trying to give herself a second chance at keeping him safe.
Dooley, Thompson, and Sousa meet in the hall and Sousa says he believes her. Thompson and Dooley accuse him of going soft, and Dooley instructs them to check the building across the street just in case. They take a team over and Dooley asks Dr. Ivchenko to close the window. The doctor questions him and Dooley plays it off, but he sees the men heading across the street. He hypnotizes Dooley and takes control of his mind. He has him lock Peggy and Jarvis in an interrogation room, handcuffing them to the table. He thenhas Dooley take him to the lab and get all of the scientists out. They look for Stark's invention number 17 and the doctor also takes a mysterious vest. He has Dooley walk him out and put on the vest.
Meanwhile, the agents dispurse in the building and Thompson tells Sousa that if he sees this woman, shoot to kill. After seeing what the little girl did to them in Russia, he's afraid to see one all grown up. Sousa runs into Dottie as she tries to escape. They fight and he shoots at her but she gets into the stairwell. The agents try to get her, but she kills one in her escape. The doctor picks her up and they drive away. Sousa finds the dead dentist and sees where she and the doctor have been communicating. He finds her messages, including one with that says to kill Peggy.
Jarvis and Peggy break the mirror to try and get out, but they realize they're still handcuffed to the table. Thompson hears the noise and comes in, letting them go. They rush to find Chief Dooley, who is in his office with the vest on. Jarvis immediately voices concern over Dooley wearing the vest, informing everyone that it is impossible to get off once it has been activated. They carefully get Dooley out of his office and he is angry with himself for trusting the doctor and letting him get in his head. The vest continues to heat up and gets closer to com-busting. The scientists and Jarvis can't find a way to get him out of it and Dooley accepts it. He asks Thompson to tell his wife he's sorry he missed dinner and he makes Peggy promise to catch Ivchenko. She promises and he replies with "attagirl" before taking off and shooting at a window. He jumps out just as the vest explodes. Sousa sees the explosion and rushes over only to find out that Dooley is dead.
Dottie takes the baby carriage into the movie theater and leaves it once the show starts. A gas can starts leaking from the the carriage. The people in the theater start coughing and then violently attacking one another until they are all dead.
