[Sequel to Don't mess with the Fox, but the prologue has a review of that story so it can be read standalone] After Lila getting exposed and the rest of the Gang of Secrets and Adrien learning Ladybug's identity, Marinette decides to widen the team in order to defeat Shadow Moth once and for all (Pre Season 4 finale)
Lila made a really bad decision, a terrible one actually. How did her plan to get rid of Marinette backfired to her so badly? It all started when she messed with Alya. *Set in season 4 after Sentibubbler, contains spoilers till that episode*