On the surface of the destroyed earth a young woman, Alexa, is seemingly being hunted down by two sentinels. Alexa flees to a tunnel, but the sentinels still follow.
This is all according to plan however. Alexa is part of a resistance group that has set a trap. After a robotic device kills of one sentinel, Alexa is able to stun the other.
The group wants to use the living sentinel for an experiment. By linking the sentinel to them all in virtual reality, they hope to convince the man-made creature to join the human's cause. But there isn't much time.