Sarah reevaluates the capabilities of her friend Andy's computer after he enters it in a chess competition. During the competition, Sarah meets a stranger with a history similar to hers. Meanwhile, Agent Ellison finds remnants from a past terminator battle. Can Sarah make the right decision to stop the future war... or has the decision already been made for her?
Sarah trudges through the South American jungle. When she returns to camp, a very young John is playing chess with an older soldier.
Present day, Sarah does pull-ups on a swing set and takes a handful of vitamins. Andy, the creator of The Turk, calls and wants to meet in Pasadena. He's at a chess tournament, The Turk is entered.
Cromartie, disguised as an FBI agent, goes to Charlie Dixon's home. Cromartie is looking for new info on Sarah.
Sarah tells John that Andy rebuilt The Turk. Cameron reminds Sarah that she should have killed Andy. Sarah sends John and Cameron to school, and they're to meet her at the tournament later.
Sarah arrives to a convention hall full of robots. Andy meets her and takes her to see the new Turk. He says the new one is more adaptable, but less predictable. Andy tells Sarah the winner of the tournament gets a cash prize and a military contract.
Cromartie isn't getting answers from Charlie, and Charlie's new wife walks in. Charlie swears he isn't harboring Sarah. As far as he knows, the woman he knew blew herself up in a bank eight years ago.
Students place objects and notes around a memorial for Jordan. John explains to Cameron why people write notes to the dead, to deal with the sadness. John talks to Cheri, but she doesn't stay long.
John works on a car in an auto class. A couple students give another student a hassle about some equipment and John steps in to help. The boy's name is Morris. He tells John to stay away from Cheri, her father has her on lock down.
Sarah watches The Turk compete against a rival machine. Sarah notices a man in the back of the auditorium, he doesn't fit in. Cameron arrives and looks over the other robots, she looks on with curiosity. John finds Sarah in the auditorium and fills him in on the military contract. She tells John to cheer for the rival, or Cameron will kill Andy. The rival team loses their queen and it looks like Andy will win.
Charlie's wife knows that he was lying to Cromartie. She only asks that Charlie tell the truth. Charlie tells her that he saw John and that he had broken into the house. Charlie doesn't have a plan to handle Sarah yet.
It appears as though Andy is going to win. But their rival makes a sudden move and Andy is forced to surrender in checkmate. Sarah heads back to meet Andy and bumps into the man who was lurking in the auditorium. Sarah opens the door to Andy's room to find Andy dead. Sarah chases after the man and tackles him. The man breaks free and runs down the alley. Police cars race in surround the man before he can get away. Sarah ducks behind a wall, sad that another innocent life was taken.
John hacks the police database and pulls up images of the man. The man has a barcode tattoo on his arm, he's a Resistance fighter. Cameron tells John that the man is one of John's best soldiers in the future.
Another Terminator sees the man's updated police file on a computer. Moments later, the Terminator walks up to a pair of talking police officers and assaults one. The other officer arrests him immediately.
At school, one of the counselors asks to see Cameron. The counselor asks Cameron what Jordan told her before she died. She repeats the conversation and the counselor knows Jordan was talking about the graffiti. The counselor looks concerned, and lets Cameron go.
Agent Ellison sits across from the mystery man, and shows him photos from the Resistance apartment. Ellison tells the man that a synthetic blood links all the crime scenes and asks the man for new info. As Ellison leaves, he calls for the man to be taken out of local custody. The Terminator, in shackles, walks right by Ellison.
Sarah, in a business suit, walks by Ellison at the prison. She's talking on the phone with the counselor about Cameron's behavior. Sarah nabs a badge from another person and hangs up on the counselor. She walks into the interrogation room. The man admits he knows who she is. He tells Sarah he didn't kill Andy, he only wanted The Turk but when he got to Andy's room, Andy was dead and The Turk was gone. He begs her to leave before a T-888 finds him. He tells her to find Andy's partner from the tournament. The man tells Sarah that his brother, Kyle Reese, carried a photo of her for luck. The man is Derek Reese, Kyle's brother and John's uncle.
The Terminator breaks open his cell door, then smashes open Derek's cell. But it's empty. Derek is chained inside a transport truck.
John tries to talk to Cheri outside school. She begs him to walk away. He watches her quickly walk to a car, and get in. Morris follows John and notes that he was right about Cheri. Morris takes a liking to Cameron. Sarah picks them up. They have a mission.
In the transport van, Derek pinches one end of his barcode tattoo, forcing a tiny piece of metal from under his skin. He uses it to free himself from the shackles. Sarah's car races up behind the transport. Cameron jumps on the transport and pulls the guards out of the cab. When the transport stops, Cameron and Sarah climb in the cab. Sarah sees the Terminator running to the transport in the rear view mirror and tells Cameron to take care of him. The Terminator jumps on the back of the truck, and tears the door open. Cameron pushes the man through the side, and holds him down as Sarah edges the transport near a flatbed truck. The Termintor's hand is cut off by a piece of the flatbed. John, Derek and Sarah race back to Sarah's truck. The Terminator forces Cameron out the back and is dominating the fight. Sarah fires a pistol to distract the Terminator. The Terminator turns and fires, the bullet strikes Derek as Cameron strikes the Terminator with a metal pipe. Cameron quickly takes the Terminator down and calls for the tool box. She grabs several tools and quickly removes the Terminator's memory chip from its head.
Sarah and John carry Derek into the house, he's bleeding badly. They place him on a table, but Derek doesn't want Cameron to touch him. Cameron analyzes Derek and tells Sarah she can't fix it. Sarah plans to kidnap a doctor and they have to save him. John tries to talk her out of it and Sarah reveals to John that Derek is his uncle. John runs out the front door.
Ellison goes over the events of the transport with one of the guards. Ellison can't believe his luck. He walks back to his car and notices a hand in a pile of rubble.
Sarah keeps pressure on Derek's wound, while Cameron writes a grieving letter at the table. Derek stops breathing as John walks in the door, Charlie behind him. Charlie pauses, then quickly moves to the table and begins CPR on Derek.