As Sarah (Lena Headey) is making lunch for John (Thomas Dekker) and Cameron (Summer Glau), Andy Goode (Brendan Hines) calls. He has rebuilt his chess-playing machine, the Turk, which Sarah had secretly destroyed because she feared its growing artificial intelligence. Cromartie (Garrett Dillahunt) turns up at the home of Charley Dixon (Dean Winters), Sarah’s ex, pretending to be an FBI agent. He asks Charley about Sarah and John because he thinks he is harboring the fugitives. Charlie says that as far as he knows, Sarah blew herself up eight years ago. Cromartie leaves his card. Charley’s wife Michelle (Sonya Walger) knows he was lying to the FBI man, and Charley admits that John came by weeks ago. He doesn’t know what to do if Sarah turns up.

Sarah attends the chess tournament and leaves disturbed. The new Turk is better and smarter, and if Andy wins the tournament, he will get a military contract. John meets a new friend in shop class and is curious about the mysterious Cheri, whom his friend warns not to get involved with. John thinks she is being abused at home. Cameron tries to fit in but leaves the guidance counselor puzzled by her answers to questions. Sarah notices a familiar-seeming stranger at the tournament. Afterwards, she finds Andy dead. She chases the man and tackles him, but he gets away, only to be picked up by the police. The next day, John finds him in a database, and they learn he is Future Resistance. Agent Ellison ( Richard T. Jones) questions the man.

Sarah poses as the lawyer for the stranger. He says he didn’t kill Andy. He was there to destroy the prototype and found him dead. And he knows a T-888 is after him. He is Derek Reese (Brian Austin Green), the brother of Kyle Reese and therefore John’s uncle. In a transport van, Derek picks his handcuffs. Sarah chases the van, Cameron leaps on board and stops the guards. The T-888 chases them and loses an arm to Cameron in a fight. The Terminator shoots Derek and Cameron rips out his CPU. They take Derek to the house and Sarah plans to kidnap a doctor. John is upset to meet and possibly lose his uncle in the same day. Agent Ellison finds a Terminator arm. Sarah is trying to save Derek. As he stops breathing, John returns with Charley, who begins to perform CPR on Derek.

The Terminator is the same one who was lying doggo among the bodies in the Safe House. A mechanical dog at the tournament barks at Cameron like a real dog would. The Queen’s Gambit is a move in which you sacrifice your Queen to force your opponent to sacrifice his King.