At the Hawkins home, Laura and Joe watch a newscast about the incident at Qualia. Mattie calls and tells them "it's over." She doesn't divulge her location but assures them she's fine then hangs up so Qualia can't track her. Joe shows Laura a pamphlet for a Synth-free community and recommends moving the family there to "get back to normality." Toby overhears.
At home, Karen Voss lets her charge run down and lies in bed. Sam plugs her in and stands next to the bed, waiting.
Laura smokes a cigarette in the backyard. When Joe comes out, she quickly extinguishes the cigarette and tells him that she doesn't want to move to a community where everyone "can pretend the future isn't happening." Joe says there's a three-bedroom flat for himself to give the kids a normal life "even if it's just for half the time."
Karen powers on and realizes Sam plugged her in. As Sam lies in the bed next to her, he asks if she's in distress. Karen tells him that she needs him to do something for her.
At Qualia, Dr. Athena Morrow tells "V" that she's unable to give her a body after experimenting on conscious Synths. "I can't take their lives to give you yours back," she says. "V" explains the vastness of her nature and the physical limitations she doesn't experience as a machine. Athena recounts a story from her childhood, but "V" refers to Ginny as "her" and insists she's no longer Ginny.
Hester learns that Laura has no way of reaching Mia and Leo. She charges herself and makes small talk with Laura. She says she used to be a tree surgeon-model Synth and asks Laura why she helps Synths. Laura discloses her unhealthy relationship with her mother and relates to feeling like less than a person. Hester wonders how many other humans are as open-minded and suggests violence as a method to force them.
At Qualia, "V" says she's "here" but somewhere else, too. Athena stiffens and states they won't be communicating any longer, as "V" needs to explore her evolving nature. Athena cries as "V" starts to delete Ginny's memories. "I'm not dying, just leaving," "V" says.
Laura receives a call from Mattie, who warns her about Hester. Mattie urges her to get out of the house while Hester stares at Laura.
A Synth receptionist alerts Milo Khoury to a system breech. He finds Athena and threatens to put her in jail for transferring "V" off-site. Athena maintains she had no involvement and that neither she nor Milo will ever find "V." Milo, astonished at what "V" did, insists they could have brought Ginny back and says he really was trying to do "something pure." Athena leaves.
Hester calls Mattie's phone and instructs her to have Leo come to Laura's house within an hour. If he doesn't arrive or if the cops get involved, she'll kill Laura. She hangs up and threatens to kill Laura's children if she doesn't cooperate. Laura expresses doubt and Hester scoffs at the idea that human lives might mean something to her. She knows about Niska and says she was "strong once," but she herself isn't weak.
Mia and Max warn Leo that Hester wants to kill him, but he remains confident about their close relationship. Mia mentions the chip in Hester's head can be used to kill her.
Leo and Mattie work on a laptop and learn that the Qualia chips fire electromagnetic pulses to the Synths. Mattie instructs Leo on how to permanently shut Hester down by using a phone. Leo insists on going alone, but Mia joins him. Mattie warns her not to be in close range or her own chip will activate as well.
At a children's birthday party, Sophie watches a Synth clown do tricks. A father tells Joe that he doesn't have to worry about the Synth clown hurting children the way humans can.
Hester admits to her real job at a chemical plant. Laura suggests she was mistreated and became angry as a result. She infers that if she were human, there'd be a diagnosis and treatment for her. "Everything you're feeling is very human," she says. "You're the proof that David Elster succeeded." Hester admonishes Laura's attempts at appealing to her and points a screwdriver at Laura's eye and tells her to be silent.
Astrid and Niska remain on the run from the authorities. Astrid suggests Niska help her family, but Niska worries about losing Astrid. Astrid teases Niska about being Niska's first love and reassures her she'll be waiting for her in Berlin. They share a passionate kiss.
Near the Hawkins home, Mia stays behind in a car while Leo continues on. She plans to go after him in five minutes, in case their plan goes wrong.
At a lake, Sam asks about Pete, and Karen tells him Pete's gone. Sam looks for Karen's pulse and concludes Pete's dead "like you." Karen says her body won't do what she wants and asks for his help.
Leo makes it to the Hawkins home and finds Hester holding Laura hostage. Hester says she wants to hear Leo "acknowledge the cost of your weakness" and blames him for the fallen Synths at Qualia. Before she can jab the screwdriver in Laura's neck, Leo offers a heartfelt apology and promises to spend the rest of his life making it up to her. Hester remains suspicious of his human side, but Leo says he's "always felt like one of you." Hester embraces him, then jabs the screwdriver into the back of his head – where the synthetic part of him is -- and accuses him of lying. Blue liquid and red blood seeps from his neck.
Mia rushes into the Hawkins home. She grabs the phone from Leo's pocket and activates the chips in both her and Hester's heads. Their eyes turn white as they collapse to the floor. Laura calls for an ambulance for Leo.
Niska arrives at the Hawkins home and takes in the scene. She realizes Leo's damage is to his synthetic side, though he hasn't lost much human blood. His body will survive but she remains unsure about his brain. Niska tends to Mia, who has only minutes before her mind is completely gone forever.
Laura calls Mattie, who thinks her version of the consciousness code could bring Mia back. Niska recommends uploading it online, as she won't make it home in time. Laura realizes it will awaken all Synths and insists the world isn't ready. Niska maintains it's the only way to save Mia. Mattie can't bring herself to do it, but Max gestures to the Synth family he's gathered in their train car-home and assures her it will be all right. She uploads the code, bringing Hester and Mia back online. Niska stands over Hester, who tries to choke her. Niska kills her by crushing her head in before she has the chance.
Karen sits in the passenger seat of her car, while Sam starts to drive it into the lake. Suddenly, Sam becomes conscious and cries out in fear. Karen pulls on the emergency brake and saves them.
At the birthday party, the Synth clown becomes conscious and stops performing.
At an airport, Athena observes a Synth attendant become conscious.
At Qualia, Milo's Seraphim become conscious. He stares in shock as one of the Synth children reaches out for a hug.
An ambulance arrives at the Hawkins home, as Synths in the neighborhood begin to wake up. They abandon their primary users and their jobs. Niska, Mia and Laura walk outside and observe the chaos in the streets.