In 2016, three years after the events of Chicago, San Francisco has become the next city to install the ctOS (central Operating System), which connects everyone with everything. Hacker Marcus Holloway is punished for a crime he did not commit by the upgraded ctOS – ctOS 2.0 – which categorizes him as the suspect. Realizing the system covertly brings harm to the innocent citizens of San Francisco, he decides to work with the hacking group DedSec to take down the ctOS 2.0, and Blume, the company behind it. Marcus joins DedSec and works with fellow hackers Sitara, Wrench, Horatio and Josh, and they begin using their skills to expose corrupt organizations and corporations that are secretly using stolen personal ctOS data for their own ends. The game begins with Marcus – known also by his hacker alias Retr0 – having an initiation test: deleting his own ctOS profile.
