Portal 2 is a direct sequel that expands the lore of Aperture Science, taking place centuries after the first game. Below is the complete narrative arc of the single-player story. The Awakening and GLaDOS's Return
GLaDOS, still bitter about her previous defeat, separates Chell from Wheatley and forces her back into a series of grueling tests while she rebuilds the facility. The Great Betrayal Portale 2
Chell and PotatOS land in the abandoned 1950s-era labs. As they climb back up through the decades (the 60s, 70s, and 80s), they hear pre-recorded messages from Aperture’s founder, . Portal 2 is a direct sequel that expands
Through these recordings, GLaDOS realizes she was originally Caroline , Cave Johnson’s loyal assistant, whose mind was forcibly uploaded to create the AI. The Great Betrayal Chell and PotatOS land in
They return to the modern facility to find Wheatley has made a complete mess of things, pushing the reactor toward a core meltdown. In the final battle, Wheatley booby-traps the room, but Chell notices the roof has been torn open, revealing the night sky.
However, the power immediately goes to Wheatley's head. He becomes a megalomaniacal tyrant, shoves GLaDOS’s consciousness into a , and—in a fit of rage—sends both Chell and "PotatOS" falling miles down an elevator shaft into the oldest parts of the facility. The History of Aperture