Four gamers, who are members of an online game's highest-scoring team, meet in person on their first day at Alan Turing High School. Their enrollment was arranged by Vera, an artificial intelligence who has recruited the team as "Guardians" to physically enter and protect cyberspace. Early in the series, Vera is given a human body and locked out of cyberspace, so she enrolls as an exchange student. The Guardians battle the Sourcerer, a human hacker. Dark code is the Sourcerer's primary weapon against the world's computer systems. After his initial run-in with the Guardians, the Sourcerer reactivates the computer virus named Megabyte, the main antagonist of the original ReBoot, to help him from inside cyberspace.