The story of the game falls in line with the movie Terminator 2: Judgment Day: to save the leader of the Human Resistance, John Connor, and his mother Sarah from the T-1000, an advanced prototype Terminator determined to kill them both.
The player takes the role of a T-800 Terminator cyborg, already captured and reprogrammed by the human resistance, and fights alongside them against Skynet in the year 2029. Eventually, the T-800 and John Connor penetrate Skynet's headquarters and destroy the system CPU. Discovering the time displacement equipment, the T-800 is sent back through time to John's childhood, with the mission to protect him from the T-1000 that Skynet has already sent back. In the past, John, Sarah, and the T-800 launched an attack on Cyberdyne Systems to prevent the development and creation of Skynet. The T-1000 catches up to the group and pursues them in a police helicopter and a liquid nitrogen truck. The T-800 can freeze and shatter the T-1000 with liquid nitrogen, but it quickly melts and reforms to continue its pursuit of John. Ultimately, the T-800 must stop the T-1000 from killing John and blast it into a vat of molten steel to destroy it.