Premise: "Riot At Xavier's" is a four-part storyline that ran from New X-Men #135-138 (2003). It was written by Grant Morrison and features artist Frank Quitely's last work on the title. The story centers on an original character of Morrison's, the teenage mutant Quentin Quire. According to Morrison, the storyline was inspired by a playground riot he witnessed in his youth.
Hypothesis: There were at least 100 previous episodes.