FLASH! A time bubble. Downtown, a man emerges from the tunnel, shot through the chest, bleeding. He finds clothes and hustles off.
Back in the storefront church. It's the morning after John's birthday and the explosion. Sarah gazes at John as he sleeps, untrusting of Cameron. Derek enters and warns them that it's only a matter of time before she goes bad again.
John questions Cameron. She tells him he can't be trusted anymore because he risked his life to save her. Even she agrees that it was the wrong decision. Sarah instructs John to go to school. It's uneventful and the normalcy will distract him.
But at school, everything seems trivial. John paces through the hallway at Campo de Cahuenga HS, everything so different now. It's all changed. And so John ditches class. Outside, he meets a girl from his English class, Riley. He tests her, makes sure she is who she says she is. Charismatic, Riley convinces him to buy her lunch.
Kacy, eight months pregnant, shows Sarah, Derek, and Cameron around a rental house. She lives next door and is helping the owner who left in a hurry. Sarah says they'll take it. With all the furniture.
James Ellison visits Michelle Dixon, Charley's wife. Michelle confesses that she found a gun in the house earlier. Surprised, Charley enters.
Sarah checks out the new place and takes a moment to herself. But there's no rest for the weary as her window is smashed in and the man from the time bubble enters, barely alive. Sarah and Derek try to revive him, while Cameron guards the perimeter. But "Stop Greenway," "Serrano Point," and "two days" is all he manages to get out before dying. Sarah believes that he must be a Resistance Fighter from the future, but Derek doesn't recognize him. Both strong-headed, Sarah and Derek debate what they're supposed to do - kill Greenway or save him?
Serrano Point Nuclear Power Plant. It's the future war and an H-K flies above the plant. Two soldiers fight to defend the plant, shooting down the H-K. Back in the present, Sarah, Derek, and Cameron case the same spot. In the future, the resistance controls this plant and uses it as one of their key sources of power.
Sarah and Cameron enter the plant, undercover, as janitors. Their new Supervisor shows them through the plant and warns them not to get "crapped up" or contaminated. Cameron identifies Carl Greenway as he passes by.
Much to her confusion, Charley tells Michelle the truth about Sarah Connor and the machines. He promises Michelle that he doesn't love Sarah but she slaps him anyways. Sarah's the least of their problems. Ellison warns the Dixons that they need to leave town immediately.
Riley opens up to John about her past. She, too, has jumped from high school to high school. John explains that his family is moving houses again but he's never seen the place. Recklessly, John invites Riley to come explore the new house with him.
In the Serrano Point control room, Greenway reviews the coolant levels before the test tomorrow. Sarah hits it off with Greenway under the guise of "Karen." She watches him down some pills and follows Greenway and his boss, Nelson, out. Outside, Nelson argues with Greenway about the importance of tomorrow's test going well.
Sarah (as "Karen") cozies up to Greenway at the Busted Atom bar while Cameron hustles some pool players to scan their Serrano Point IDs. Sarah learns that Greenway is the black sheep of the plant because he's suffering from cancer - and even has a scar on his arm to prove it. With them inside, Derek breaks into Greenway's car and is surprised when someone vandalizes the windshield. The guy really isn't popular amongst his co-workers. Turns out, Carl Greenway has a reputation for being overly cautious - and if he stops tomorrow's test because of a problem, the plant will likely shut down and the rest of the employees may lose their job. His boss is pressuring him to ignore the problem with the coolant, but if he does, the plant could melt down. Now it's even more unclear what Sarah, Derek, and Cameron are supposed to do.
John and Riley check out the house and discover his hilariously juvenile new room. Sarah returns home, surprised to meet Riley. She lectures John about safety and bringing someone home, but he blows her off. Instead, John and Riley take off for his room, a new friendship born.
It's the day of the test at Serrano Point. Suspicious, Sarah follows Nelson, the boss, right into a radioactive area! Nelson sends her into the room where Sarah gets crapped up, and is forced to get washed down. Humiliatingly, Nelson hands Sarah back her clothes, as it "turns out" she wasn't actually crapped up. Did he put her through it on purpose?
John and Riley wake up in the morning, surprised to have fallen asleep together. As she takes off for school, John decides he's not going to go. Even though he knows better, John gives Riley his number and instructs her to use the "code."
Ellison sees off Charley and an upset Michelle. Ellison hands him a Bible, while Charley asks him his own plan. "We'll see..."
With the test upon them, Greenway has changed his ways, insisting that "everything is fine." When Sarah notices the scar on his arm has gone missing, she checks in with Derek, inside Greenway's house. There he finds Greenway, hanging. Greenway in the plant has been replaced by a Terminator!
T-Greenway reeks havoc in the plant, busting open a water valve to melt down the plant. Sarah grabs Cameron for help, who is unsure what to do -- she's still glitchy from the jeep explosion! With the plant falling apart and the reactor overheating, Derek hustles to make it over.
Cameron attempts to re-close the water valve, resulting in a fight with T-Greenway, while Sarah and Derek try the manual to fix the problem from the control room. On a closed circuit monitor in the control room, Sarah spots Cameron and T-Greenway fighting, grabs a machine gun from a security officer, and heads after them...
...but to get there she must go back through the radioactive room! In a hurry, she hesitates, but eventually makes her way through it...
And then, through the haze of smoke appears Sarah Connor, machine gun blasting at T-Greenway. Cameron forces him back, causing a firey blaze, and his skin burns off and destroys his endoskeleton. Sarah holds the gun at Cameron, asking her if she's okay. Has the machine reverted again? "I'm okay," replies Cameron. No, she hasn't reverted. Not now at least.
Cameron scans Sarah again for radioactive material. Previously, Cameron told her she dies of cancer. Is this how it happens? Cameron doesn't know. Sarah wonders what she's supposed to do. Is she supposed to wait for the cancer? Just wait for the worst like a time bomb that could go off at anytime? Cameron, too, wonders the same thing about her own fate.
Inside, John warns Cameron not to creep Riley our and tells her he has nothing to prove to her or anyone else. Then, his phone rings. It's Riley, just practicing the "code." John smiles, that bit of normalcy slowly creeping into his life...
Sarah spots blood on the staircase outdoors, a trail left by the Resistance Fighter in the beginning. More on the doorway to the basement. Inside, a wall:
Names, numbers, people, places. All written in blood. A list from the future.
Sarah showers, washing away the day and the radioactive materials. With this list she's more sure of her mission but now even more unsure of her fate...
A press conference is held outside Serrano Point power plant by the CEO of Automite Systems. There he announces that machines will replace workers in the control room of the plant in order to eliminate human error. Entering his car, the CEO morphs into Catherine Weaver, the T-1001!