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. Sometime 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 orchestrates an attack on a Skynet base, where he discovers prisoners and schematics in a laboratory for incorporating living tissue into a new type of Terminator, which he recognizes as the T-800 model. John survives an explosion on the base, which is destroyed. Following John's departure, Marcus emerges from the base's wreckage and begins walking toward 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 that they believe can initiate a shutdown of Skynet's machines. The Resistance plans to launch an offensive against Skynet's headquarters 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 kill the Resistance's leaders within the same time frame. John learns he is second on this list, following Kyle Reese. The Resistance leaders do not understand Kyle's importance, but John knows that Kyle will eventually travel back in time and become his father and realizes that Skynet has learned this.
Arriving at the ruins of Los Angeles, Marcus encounters Kyle and a mute child named Star during a skirmish with Skynet's machines. Kyle and Star are subsequently abducted and taken prisoner by Skynet. Two Resistance A-10 airplanes are shot down while trying to intercept a machine transport. Marcus locates downed pilot Blair Williams, and they make their way to John's base, where Marcus is wounded by a magnetic land mine. Attempting to save his life, the Resistance fighters discover that Marcus is a cyborg, with a cybernetic endoskeleton and a partially artificial cerebral cortex. Although Marcus insists that he is human, John and his wife Kate suspect that Marcus has been sent to execute them, and John 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 awaits John's signal. Marcus enters the base, interfaces with the computer, and disables perimeter defenses so that John can release the prisoners. Marcus learns from Skynet (which assumes the form of Dr. Kogan on a screen) that he was resurrected by it to lure John to the base; when the Resistance launches its attack, John will be killed, achieving Skynet's goal. The hidden signal that the Resistance received earlier is revealed to be a ruse, and Skynet uses it to track down and destroy the Resistance command submarine.
Refusing to accept his fate, Marcus tears out the hardware linking him to Skynet and leaves to aid John. John locates Kyle and Star, but they are ambushed by a T-800 Terminator. As Kyle and Star escape, Marcus appears and fights the T-800 while John rigs together nuclear fuel cells to destroy the facility. Marcus is soon outclassed in strength and temporarily disabled until John comes to his aid, after which John is stabbed through the chest by the T-800 from behind. Marcus destroys the T-800 by tearing its head off and he, John, Kyle, and Star are airlifted out. John detonates the explosives, destroying a stockpile of Skynet's weapons, including the T-800s, with the base.
At a field hospital, John's injury is deemed terminal, so Marcus offers his 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 continues.
RATING: 10 STARS