Terminator Salvation is a 2009 American science fiction action film directed by McG and starring Christian Bale and Sam Worthington. The fourth installment in the Terminator series, the film is set in 2018 and focuses on the war between Skynet and humanity, with the human Resistance fighting against Skynet's killing machines. This is a departure from the previous installments, which were set between 1984 and 2004 and used time travel as a key plot element. Bale portrays John Connor, a Resistance fighter and the franchise's central character, while Worthington portrays cyborg Marcus Wright. Terminator Salvation also features Anton Yelchin as a young Kyle Reese, a character first introduced in The Terminator, and depicts the origin of the T-800 Model 101 Terminator.
In 2003, Doctor 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. 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" (as depicted in Terminator 3: Rise of the Machines). In 2018, John Connor (Christian Bale) leads a Resistance attack on a Skynet base. John discovers human prisoners and schematics for a new type of Terminator incorporating living tissue, but he is the only apparent survivor of the attack after the base is destroyed in a nuclear explosion. However, Marcus emerges from the wreckage of the base and proceeds on foot to Los Angeles. John returns to Resistance headquarters located aboard a nuclear submarine and tells General Ashdown (Michael Ironside), the current leader, of his discovery. Meanwhile, the Resistance has discovered a radio frequency believed to be capable of shutting down Skynet machines. 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 a week's time. John learns that his own name is second on the list, following a civilian named Kyle Reese. The Resistance leaders are unaware of Kyle's importance to Skynet, but John knows that it is because Kyle will later become his father (as depicted in The Terminator). John meets with his wife Kate (Bryce Dallas Howard) and his officer Barnes (Common), and transmits a radio broadcast to Resistance members and surviving civilians around the world. 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). Kyle relates to Marcus the events of Judgment Day and the ensuing war between humans and machines. Hearing John's radio broadcast, the three leave Los Angeles in search of the Resistance. They survive an attack by machines, but Kyle, Star, and several other humans are taken prisoner, while a pair of Resistance A-10 planes are shot down. Marcus locates downed Resistance pilot Blair Williams (Moon Bloodgood) and they make their way to John's base, but Marcus is wounded by a magnetic land mine. 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 believes himself to be human, demanding to be released so that he can save Kyle from Skynet, but John believes that Marcus has come to kill him and orders his destruction. However, Blair releases Marcus and helps him to escape from the base. During the resulting pursuit Marcus saves John's life from Skynet hydrobots, and the two form an alliance: Marcus will enter Skynet's headquarters and attempt to disable its defenses so that John can rescue Kyle. John demands that Ashdown delay the attack so that he can rescue Kyle and the other prisoners, but Ashdown refuses and relieves John of his command. However, John's soldiers remain loyal to him and obey his command not to attack the Skynet base. Marcus enters the base, interfaces with the computer, and disables the perimeter defenses so that John can infiltrate the cell block and release the human prisoners. Marcus discovers that he was created by Skynet in order to lure John into the base; when the Resistance launches its attack, John will be killed, achieving the goal that Skynet and its machines have failed to accomplish so many times. The radio signal that the Resistance's plan depends on is a ruse on the part of Skynet, which uses the signal to track down and destroy the command submarine with the Resistance leaders aboard. Marcus tears out the hardware linking him to Skynet and assists John in battling a T-800 model 101 Terminator. John is mortally wounded during the fight, but succeeds in destroying the Skynet base by rigging several Terminator fuel cells to an explosive, detonating them as he, Marcus, Kyle, and Star are airlifted out. Kate attempts to save John's life, but his heart is too damaged. Marcus offers his own heart for transplant, sacrificing himself to save John. Recovering, John radios to the other Resistance fighters that though this battle has been won, the war is far from over.