Sarah, captured and jailed as a fugitive, sits alone in a police interrogation room. Detective Auldridge enters, reciting her rights again; she is silent while he lists her offenses: 1. Ten years ago she murdered Miles Dyson. 2 Eight years ago she and her son and "high school friend" (Cameron) blew up a bank vault. 3. She participated in a firefight in which five were killed, and she kidnapped Savannah Weaver. Sarah's only response is, "You're a funny boy." He threatens to bring her son in alive or dead; she insists he is dead. He leaves; Sarah gazes at the security camera.
Television coverage of Sarah's arrest is watched by an anxious John, hiding in a motel with Cameron. He wants to move again; Cameron says that would involve high risk. John needs a computer for research, but not, as Cameron suggests, to map out the L.A. County Jail, but to research shielded nuclear power sources, like hers. He suspects Sarah may have been exposed to that radiation, causing cancer.
Elsewhere, the T which attacked the Weaver residence is alone, doing self-surgical repair on its injuries - it watches the tv news of Sarah's capture.
In the ZeiraCorp lab, Murch and John Henry play a board game of strategy with small figures. John Henry quickly learns to roll the game piece with a higher total, and even smiles slightly at his success. Weaver enters to talk to Murch - about preparing all the hardware for shipment, in case John Henry is attacked again. Murch thinks a move is a bad idea - they recently changed a simple wire, which "tweaked" John Henry. Even a small hardware change modifies John Henry.
At the jail, Ellison is admitted to the interrogation room to see Sarah. He was under suspicion of being involved with Sarah's crimes, but he talked his way out of it. The police followed him to the movie theatre where Sarah released Savannah to Ellison - he claims he did not know he was followed. They both were concerned about Savannah's safety. He urges her to tell the police everything, but she tried that once...leading to incarceration in a psych ward. Maybe things would be different now, he asserts, but Sarah believes there is always something to lose. As Ellison leaves, Sarah insists that Savannah is not safe, a statement she repeats to the watchers. And this same camera view is being watched by John Henry, who has tapped into the county jail's security system, and Weaver, at his side.
In the jail, Ellison discusses Sarah with Detective Auldridge, who believes that Sarah is a liar with a guilty conscience. She has asked for a priest, Father Armando Bonilla, and the police cannot monitor her conversation with him. Father Bonilla arrives at the interrogation room - does he remember her? They had found sanctuary in his parish months earlier. She bluntly asks him if he believes in the Devil. Something that opposes God, he replies, but Sarah is talking about a Devil who wants the world to burn. You saw things, she says, and he continues to pray to understand. She offers to explain, after which she will ask him to do something for her.
Ellison returns to the lab to find John Henry and Weaver, both watching the county jail video of Sarah meeting with a priest. Ellison is perturbed, but Weaver explains that JH monitors all law enforcement channels. He thinks it is illegal; Weaver responds that lying to the FBI is also illegal. Weaver continues her pretense that she is a concerned mother, and wants to meet John Connor, who may know something about the attackers. JH begins repeating Weaver's statements, so Ellison and Weaver move to the hallway to continue. Weaver wants to know why John was at her house when the attacker struck, why Sarah believes her son is a Messiah, and suspects that his cyber companion are connected to the JH body. She tells Ellison not to pretend that he did not know that Cameron was a cyborg. Ellison does not know how to find John; Weaver does.
At a gun shop, the T enters and places two pistols on the glass counter - when asked if he wants ammo, he replies, "Silencers." When the shop owner replies that they cannot sell them, the T places a wad of bills down. He writes a number, "Ask to speak to Manny." The T repeats, in purely logical T fashion, "I want to talk to Manny." Call the number first, the owner replies. The T leaves.
At the motel, John asks more questions of Cameron about Sarah's weight loss - it amount to 11% of Sarah's body mass in six weeks. Cameron explains that she would know if her power source was leaking radiation - she has sensors for that, but they are not visible. John enumerates some of her flaws - killing birds, trying to kill him..."You're a machine." John's phone rings, it is Father Bonilla.
At the parish, Father Bonilla enters the confessional, a young woman enters, and he explains that an envelope is under the bench - it was all he could find, hoping it is enough. And he has a message for her. She leaves the parish - outside Ellison is watching.
The motel lights flicker from red to blue, reflecting on Cameron's face. A knock on the door - they grab weapons and open it - a young woman is allowed to enter. She has brought passports for Cameron and John - they are perfect, but John was looking for a message from Sarah - there is none, the woman explains. The message is, "Leave this place, as soon as it is safe. Do not come for her...leave." "We lose everybody we love," she says, as she turns to go. Cameron spots something interesting outside, in a moment she returns with Ellison, there following the woman. He explains he had nothing to do with Sarah's arrest, and that Weaver wants to meet John. He is unwilling - so Ellison is left with one question - for Cameron, from Weaver. "Will you join us?" But neither John nor Cameron know what the question means, and Cameron tells Ellison to leave. John was not upset by Ellison; he believe Cameron was - but she repeats his statement - "I'm just a machine."
At the jail, Sarah sits in a dark cell - Det. Auldridge enters. "I believe you," he says, about machines from the future, time travel, cyborgs, and he has seen how they have not aged in the last 10 years. He wants to help, but she refuses, saying only that her son is dead. He asks her about Danny Dyson; she knows nothing, but Danny has been missing for three months.
At ZeiraCorp, the T drives into the parking garage, exits the Cadillac, and shoots down a security guard. Weaver steps forward, the T fires several shots into her, without effect, as the LM figure absorbs the rounds. The T is puzzled - Weaver's arms morph into long spikes, one of which she stabs into the T, the other into a power panel, transmitting a huge voltage surge into the T - it falls to the concrete. Soon, in the lab, JH examines the chip from the T's head - it is treated to self-destruct on contacting oxygen. Weaver asks if the data can be recovered, to learn who sent the T. JH replies, "It's safe to assume my brother sent it." Ellison enters, Weaver disappointed in his lack of success in arranging a meeting with John Connor.
John awakes suddenly to find Cameron hovering over him, ready to explain how her chip and the body works. Both hardware and software are designed to terminate humans, and deep inside her, she still wants to kill John. "Then why don't you?" he asks. She will show him this body - she disrobes and lies on the bed, asking John to get on her. She pulls her knife - telling him where to cut. "If I am damaged," she says, "we should know." He cuts, and reaches inside, finding a mechanism - which is cold. That's good, she says. "John," she says, with a long pause - "It's time to go."
Father Bonilla receives a call from the young woman, and he returns to the jail to speak to Sarah. She had tried to provide passports to help John and Cameron escape, but their message for Sarah is, "She's coming." They hear sounds of a disturbance in the corridor - the room is locked. Outside, Cameron, armed with a pump shotgun, enters the halls, firing at the guards, blowing glass away, impervious to automatic weapons fire, but she is not killing them. John Henry brings up a schematic of the jail security system - the cells doors begin to open everywhere - the prisoners run into the corridors, seeking to escape. Cameron, badly damaged by gunfire, finds Sarah, while Weaver and John Henry watch - finally spotting Sarah, meeting Cameron. Outside John pulls up in a vehicle, Sarah and Cameron escape with him. Sarah is angered by the rescue, and they are all concerned about Cameron being "less than 100 percent," because Sarah needs her to destroy whatever is in the ZeiraCorp basement.
John and Sarah sit in the hall in the corporate building - waiting for Weaver. Cameron thinks Sarah is sick, John tells her. Ellison arrives - John says, "I love you," to Sarah, as they enter the elevator with Ellison. Cameron remains in the car, they tell him - Ellison asks if Sarah is armed. But below, Cameron has already entered the basement, and opens the door to find JH waiting for her. "Hello," they say to one another. "Will you join us?" JH asks. Cameron brings out her knife, and closes the door.
Above, in Weaver's office, she explains to John that they have a common enemy, one they cannot fight with conventional weapons. She abruptly cuts off Sarah, speaking to John about Skynet, and their cyborg (Cameron) who is skulking around in her basement. Behind Weaver, in the distance, a drone rapidly approaches, directly toward the building. Weaver calls out, "Get down," as the drone crashes through the window, and she transforms into a metal shield, protecting Sarah, Ellison, and John from flames and flying debris. "Run," the LM Weaver shouts. As Weaver returns to her human form, the stranded eel from the shattered aquarium slides across the debris-covered floor, morphs into LM, and is absorbed by Weaver.
They run for the basement, Weaver following them, as Sarah says they are trying to kill her son. No, replies Weaver, they are trying to kill her son. She (Cameron) has already done it, Sarah says, but Weaver insists "Your John may save the world, but he can't do it without mine." They burst into the lab where the damaged Cameron is motionless, John Henry gone. John examines her hurriedly - her chip has been removed, by John Henry, he yells. But Weaver counters, "He didn't take the chip, she gave it to him." On the monitor, a sentence repeats, "I'm sorry, John."
Where is John Henry? Weaver explains - "Not where, but when." Sarah sees a hardware unit - it's the Turk, the beginnings of Skynet. Sarah viciously accuses Weaver of building Skynet, but Weaver responds, "No, I was building something to fight it." Weaver asks Ellison if he is ready - but he has seen enough. Weaver makes instrument settings, telling Ellison to pick up Savannah after gymnastics, as electrical discharges begin - Sarah steps back, while John is compelled to remain in the forming time bubble with Weaver and Cameron, to find John Henry, to find Cameron's chip. "I'll stop it," Sarah says to John as the bubble begins to coalesce into a blue sphere.
In an unknown place, and unknown time, John and Weaver arrive in the time bubble. "Where's Cameron?" he asks urgently. "It doesn't go through," Weaver replies. John finds clothing as a search team with dogs passes nearby. An armed man stops John; Weaver is suddenly gone, while John insists he is "not metal." Another man approaches - it is Derek, but he does not know John, only that this young man is human. John is speechless, joyous to see his uncle alive. John Connor is a name they do not know in this alternate future - Derek states that John will be famous - his brother is back, and John is wearing his coat. John turns - to see a man approach...Kyle Reese, his father. And behind him is Cameron, restored...or is it Allison?
At the fiery circle, remaining from the time bubble, where John and Weaver entered this alternate future, one last spark can be seen, combined with a voice...it is Sarah's voice coming through one last time, speaking to John, now lost to her. "I love you, too."