The Connors move out of their house. Sarah (Lena Headey) stashes John (Thomas Dekker) at a lighthouse on the coast that not even Derek (Brian Austin Green) and Cameron (Summer Glau) know about. Sarah’s ex, Charley Dixon (Dean Winter), meets them there.
John Henry (Garret Dillahunt) is malfunctioning. Mister Murch (Shane Edleman) shuts him down. Catherine Weaver (Shirley Manson) and James Ellison (Richard T. Jones) arrive and Murch tells them an outside force tried to kill John Henry. Catherine reactivates him. John Henry says the power that tried to do him in was identical to that of Cyberdyne Systems.
As they are packing up for storage, Cameron tells Derek about Jesse’s miscarriage. Sarah discovers a lump in her breast and checks into a hospital. It’s not a lump; it’s a transmitter. Armed men appear at the Connors place and the hospital. Sarah breaks the transmitter with a defibrillator, knocking herself out, then comes to and disables her attacker. She is one tough babe.
John and Charley are warned by Charley’s security system. They flee the flying bullets. John boards the boat and Charley blows up the dock. Derek and Cameron are trailed by a truck. Investigating, Derek is tasered and captured. Cameron chases after the truck, catches up at a warehouse, and is electrocuted. Before her attacker can remove her chip, she comes to, chokes the man, and frees Derek. Sarah returns to the lighthouse, finds the aftermath of the battle. She notices the boat gone but finds Charley’s body in the water.
The wire in Sarah was put there by Ed Winston when she was his captive and unconscious. The three gunshots on Charley’s chest are in the three-dot pattern Sarah is obsessed with. It seems Skynet may already be alive. The lighthouse is the Point Vincente Lighthouse in Rancho Pales Verdes, California. To the Lighthouse is a 1927 novel by Virginia Woolf. Charley reaches the logical end of getting involved with the Connors, having lost everything else in his life.