A race of merciless androids from Earth's future send a Terminator back into the twentieth century to kill Sarah Connor, the mother of the man who would one day lead the human resistance movement.
With John Connor now a teenage boy, another Terminator -- the advanced T-1000 -- is sent back to kill him before he can realize his destiny. But the original Terminator has also been sent back in time ... this time, to protect John and Sarah.
Now in his twenties and facing the approach of the war with the machines, John Connor must again avoid the latest and most powerful model of Terminator -- the seductively feminine T-X -- with help once again from the older T-800 model.
In the near future John Connor fights for the Resistance and tries to encourage others to stand up against the machines -- but the survivor of an experiment in the past may threaten everything he thinks he knows about his enemy.