While Sarah, John and Cameron track another name from their list, they accidentally cross paths with T-1001. Meanwhile, a woman who Derek once knew in the past surprises him by appearing in the present.

The Connors find themselves on high alert and in odd company after their house is robbed. A Terminator terrorizes Ellison, while another gets dangerously close to John Connor. Derek and Jesse continue to get reacquainted.

Sarah finds that the strange dreams she's been having while she sleeps are slowly beginning to creep into her waking life, but she has no idea what the dreams mean for her and John. Derek and Jesse investigate a possible Skynet conspirator.

Sarah's quest to find the meaning behind the "three dots" leads to a technology firm seeking an advanced microchip. Meanwhile, Jesse comes clean to Derek about her mission and Weaver makes an important introduction.

Terminators come after a family whose unborn daughter plays an important role in the war against the Machines, and Sarah, Cameron, and Derek try to protect them.

Sarah turns to a UFO convention for answers about the "three dots," more details about Riley's mission are revealed, and Ellison begins working with Catherine Weaver's AI prototype, "John Henry."

While fighting to stay alive, Sarah is guided by the image of John's father. Weaver's attempt to protect John Henry has deadly consequences.

While Derek does surveillance on a lawyer he suspects may be connected to Skynet, Sarah and Cameron begin to have doubts about Riley.

As the Connors prepare to move, they find out that Riley is dead, and Sarah begins to doubt Cameron's motives. Jesse flashes back to a submarine mission in the future, and John Henry plays hide and seek with Catherine Weaver's daughter.

Jesse's submarine mission in the future takes a fatal turn with unforeseen consequences. Back in the present, her plan to turn John against Cameron backfires when John discovers that Jesse--not Cameron--killed Riley and he makes a life-or-death decision.