Sarah takes her son, John, to a small town in New Mexico, where he befriends the person who will become his protector.

Sarah makes contact with an old friend to ask a favour; John decides to pay a visit to Sarah's ex; Cameron makes a new friend; together they infiltrate a resistance safe house and discover they are not alone.

Sarah calls on Miles Dyson's widow in her quest to find Skynet's creators; John and Cameron make brave attempts to fit in on their first day at the new high school.

When Sarah, Cameron and John track down stolen cargo, John becomes separated, leading him to discover the future isn't as safe as he had hoped; Agent Ellison's murder investigation leads him to an interesting suspect.

When Sarah re-evaluates the capability of Andy's computer, she worries about where it could lead; Sarah meets a stranger whose history is tied to hers; agent Ellison discovers remnants from a terminator battle.

The stranger, fighting for his life and flashing in and out of consciousness, recalls his future life battling the machines in 2027; Sarah tries to explain the past to Charlie.