Attempting to save his life, the Resistance fighters discover that he is in fact a cyborg with human organs, a mechanical endoskeleton, circuitry, and a partially artificial cerebral cortex. Marcus locates downed pilot Blair Williams (Moon Bloodgood) and they make their way to John's base, but Marcus is wounded by a magnetic land mine. The Resistance sends a couple of A-10 Warthogs which are shot down by an HK. The Moto-terminators are destroyed in the chase but Kyle and Star are captured by the Harvester. Marcus and Kyle try to escape but are followed by Moto-terminators and an aerial HK. The compound is suddenly attacked by a Harvester which grabs Virginia and a few others. The man who meets them is hostile and refuses to lend them food or gasoline, but the compound's leader, Virginia, refuses to let the trio leave until Star gets some food. In the desert, Kyle spots a Resistance symbol at a seemingly abandoned 7-11. They manage to destroy it and escape into the desert. On the way, they are spotted by a Skynet spy drone that identifies Kyle. Hearing John's radio broadcast, the three leave Los Angeles in search of the Resistance. Kyle relates to Marcus the events of Judgment Day and the ensuing war between humans and machines. Arriving in the ruins of Los Angeles, Marcus is saved from a T-600 Terminator by Kyle Reese (Anton Yelchin) and his mute companion Star (Jadagrace Berry). John meets with his officer Barnes (Common) and wife Kate (Bryce Dallas Howard) and sends radio broadcasts to Resistance members and surviving civilians around the world. The Resistance leaders are unaware of Kyle's importance to Skynet, but John knows that it is because Kyle will later become his father (see The Terminator). John learns that his own name is second on the list, following Kyle Reese. They plan to launch an offensive against the Skynet base in San Francisco in four days, in response to an intercepted "kill list" indicating that Skynet plans to kill the Resistance's command staff in four days' time. Meanwhile, the Resistance has discovered a radio frequency capable of shutting down Skynet machines. John returns to Resistance headquarters located aboard a nuclear submarine and tells General Ashdown (Michael Ironside), the current leader, of his discovery. However, Marcus emerges from the wreckage of the base and proceeds on foot to Los Angeles. John discovers human prisoners and the plans for the development of a new type of Terminator incorporating living tissue, but is the only apparent survivor of the attack after the base is destroyed in a small nuclear explosion. In 2018, John Connor (Christian Bale) leads an attack by the Resistance on a Skynet base.
One year later, the Skynet system is activated, perceives humans as a threat to its own existence, and eradicates much of humanity in the event known as Judgment Day (see Terminator 3: Rise of the Machines). Serena Kogan (Helena Bonham Carter) of Cyberdyne Systems convinces death row inmate Marcus Wright (Sam Worthington) to sign his body over for medical research following his execution by lethal injection. The synopsis below may give away important plot points. But Marcus steps on a mine and is submitted to surgery, when a secret about his origins is disclosed. When Kyle is captured by a machine and brought to the Skynet headquarters, Marcus decides to help the youngster and heads to Skynet on the way, he saves Blair Williams who suggests to him that he should meet John Connor first.
Meanwhile the resistance discovers a signal that might turn-off the machines and John offers to test it. Marcus befriends the teenager Kyle Reese and the girl Star who help him to survive the lethal machines and they travel together in a Jeep.
Out of the blue, Marcus appears naked and with amnesia in the location. In 2018, after an unsuccessful attack to a Skynet facility, only John Connor survives, but he discovers that Skynet is developing the powerful new model T-800. Serena Kogan to donate his body to her research and he accepts. In 2003, in the Longview State Correctional Facility, the criminal Marcus Wright is on death row, and is convinced by the cancerous Dr. But whose side is he on, and can he be trusted?
In 2018, a mysterious new weapon in the war against the machines, half-human and half-machine, comes to John Connor on the eve of a resistance attack on Skynet.