Terminator Salvation is a 2009 American science fiction war film and the is the fourth (and last film) in the original Terminator film franchise continuity with 2015's Teminator Genisys using time travel to erase the events of the original continuity in a soft reboot.
Plot[]
In 2003, Dr. Serena Kogan of Cyberdyne Systems convinces death row inmate Marcus Wright to sign over his body for medical research following his execution. One year later, the automated Skynet system is activated, and becomes self-aware; perceiving humans as a threat to its existence, it starts a nuclear holocaust to eradicate them in the event known as "Judgment Day".
In 2018, John Connor leads an attack on a Skynet base, where he discovers human prisoners and schematics for a new type of Terminator, incorporating living tissue, the T-800. John survives a violent assault on the base, which is destroyed. Following John's departure, Marcus emerges from the base's wreckage and begins walking towards Los Angeles.
John returns to the Resistance headquarters located aboard a nuclear submarine and is briefed by General Ashdown that the Resistance has discovered a hidden signal containing a code protocol which they believe can initiate a permanent shutdown of Skynet's machines. Working on this intelligence, the human militia plans to launch an offensive against the Skynet base in San Francisco. It is decided among the Resistance that the offensive will commence in four days, due to an intercepted kill-list created by Skynet, which plans to terminate the Resistance's command staff within the same time frame. John learns he is second on this list, following Kyle Reese. The Resistance leaders are unaware of Kyle's importance, but John knows that Kyle will eventually travel back in time and become his father (as seen in The Terminator), and realizes that Skynet has learned of this fact.
Arriving at the ruins of Los Angeles, Marcus encounters Kyle and a mute child named Star during a violent skirmish with Skynet's machines. Kyle and Star are subsequently abducted and taken prisoner by Skynet. Later, two Resistance A-10 airplanes are shot down while trying to intercept a machine transport. Wright locates downed pilot Blair Williams. They then make their way to John's base, where thereafter, Marcus is wounded by a magnetic land mine. Attempting to save his life, the Resistance fighters discover that Marcus is indeed a cyborg, with a mechanical endoskeleton and a partially artificial cerebral cortex. Although Marcus believes himself to be human, John and his wife Kate think that Marcus has been sent to execute him and orders him to be killed. Blair helps Marcus escape. During the pursuit, Marcus saves John's life from Skynet's hydrobots and the two make a bargain; Marcus will enter Skynet's headquarters in San Francisco, to help John rescue Kyle and the other prisoners, if he lets him live.
John pleads with General Ashdown to delay the offensive so he can formulate a plan to extract the human captives, but Ashdown refuses and relieves John of his command. However, the Resistance disobeys Ashdown's orders and instead, await John's signal. Marcus enters the base, interfaces with the computer, and disables perimeter defenses so that Connor can infiltrate the cellblock and release human prisoners. Wright learns from Skynet (which assumes the form of Dr. Kogan on a screen), that he was created and built from the original Wright's corpse to lure John to the base; when the Resistance launches its attack, John will be killed, achieving the goal that Skynet had failed to accomplish in the past. The hidden signal that the Resistance received earlier is revealed to have been a ruse, and Skynet uses it to track down and destroy the command submarine with the Resistance's leaders aboard.
Marcus tears out the hardware linking him to Skynet and assists John in battling the new T-800 (Model 101) Terminator. Marcus is soon outclassed in strength and temporarily disabled until John comes to his aid. Marcus eventually defeats the T-800, while John destroys the Skynet base by rigging together explosives. John, Marcus, Kyle, and Star are airlifted out. John though was seriously wounded during the assault with a life-threatening injury to his heart. Marcus offers his own heart for transplantation, sacrificing himself to save John. As he recovers, John radios to other Resistance fighters that, although this battle has been won, the war is still not over.