John's 16th birthday forces him to confront his destiny alone. Meanwhile, Agent Ellison faces off with his faith and the Feds, in the aftermath of Cromartie's massacre, and a new player is introduced, Catherine Weaver, the CEO of a high-tech corporation.
Sarah and Cameron investigate a nuclear power plant. John's social life takes a front seat to academics with the help of his new found friend. Meanwhile, Catherine Weaver gains another piece of the puzzle for her pet project.
Cromartie kidnaps Charley's wife and Sarah and Derek get put to the test. Sarah and Derek must outsmart Cromartie to ensure a safe rescue. Meanwhile, John is a predicament of his own when he is caught between Cameron and Riley.
A glitch in the software causes Cameron to forget who she is. She goes missing and is taken in by a kid named Jody. Cameron and Jody end up at a halfway house where Cameron meets with a social worker who uncovers some distant memories. Catherine Weaver meets with Agent Ellison to discuss his future at Zeira Corp, and Ellison looks into Weaver's past.
John and Derek infiltrate a military academy in order to protect an important member of the future resistance. Meanwhile, Weaver's first assignment for Ellison takes a turn of events when he discovers a specter from his own past.
Sarah, John and Cameron try to determine what a T-1001 would need with a doctor as they track down another name on their list. Meanwhile, a woman from Derek's past surprises him in the present.
The Connor’s are on high alert after their house is robbed. Meanwhile, one Terminator terrorizes Ellison, while another gets close to John Connor. Finally, Derek and Jesse continue to get closer.
John and Riley's trip across the border has deadly results. Meanwhile, Sarah and Ellison finally meet in person.
Sarah's mystifying nightmares creep into her real life. Meanwhile, Derek and Jesse investigate a possible Skynet conspirator.
Cameron's surprising, secret life is revealed. Also, history is forever changed when a Terminator is sent back to the wrong time.