In search for his father who disappeared 20 years ago, Sam (Garrett Hedlund) is transported into the virtual gaming world his father had created. There, he meets his father’s evil alter virtual ego, Clu (young Jeff Bridges), who wants Flynn’s (older Jeff Bridges) memory disk to rule both the virtual world and escape to the real world and essentially take it over.
With the help of one of Flynn’s ISO program creations Quorra (Olivia Wilde), Sam convinces his father to go back through the portal where he came from, return home and shut down Clu and the gaming world for good. Sam, Flynn and Quorra, make it to the portal, but as they are about to go through, Clu shows up and steals Flynn’s memory disk. However, Flynn switched his with Quorra’s. When Clu realizes he has the wrong one, he charges at Quorra, but Flynn uses his powers to draw Clu to him. When they collide, they explode, killing them both. Sam and Quorra pass through the portal and back in Flynn’s old office, Sam downloads and presumably kills the virtual program.
In the end, Sam and Quorra ride off into the sunset, which from earlier in the movie, is what Quorra always dreamed about.