In a world still reeling from the past specter of technological armageddon, humanity finds itself once more on the verge of a cataclysm wrought by the machines. A new, advanced Terminator, the T-X, is sent back through time with a mission to eliminate key human resistance leaders before they can rally against the self-aware artificial intelligence, Skynet. This lethal machine is more sophisticated and dangerous than any of its predecessors: a morphing metal endoskeleton with built-in weaponry and the ability to remotely control other machines.

Unbeknownst to the future saviors of the human race, their survival hinges on the actions of two protectors from the future. A reprogrammed T-101 Terminator is sent back to defend John Connor, the destined leader of the human resistance, and his future lieutenants. Connor, now living off the grid to avoid detection, finds himself once again targeted for termination. Together with a former classmate and unexpected ally, Kate Brewster, whose fate is also entwined with the resistance, they must evade the relentless pursuit of the T-X. The safety of these two individuals is crucial if humanity is to have any chance of avoiding the impending doom of Judgment Day. The T-101 must protect John and Kate at all costs, as they navigate the treacherous path of survival while the very fabric of civilization teeters on the brink of collapse.