The Heroes of Olympus is a fantasy series written by Rick Riordan, set in the same universe as the Percy Jackson series. The central conflict revolves around the clash between the Greek and Roman demigods, as their ancient worlds collide and a new prophecy unfolds. The main characters include Percy Jackson, Annabeth Chase, Jason Grace, Piper McLean, Leo Valdez, and many others who must join forces to prevent an impending war and save the world from destruction. To get a more detailed understanding of the central conflict and main characters, I recommend reading the series or exploring summaries and analysis available online.
The central conflict in "The Heroes of Olympus" series revolves around the resurgence of Gaea, the primordial goddess of the Earth, and her plan to overthrow the Olympian gods and dominate the world. The main characters are a group of demigods from Camp Half-Blood, including Percy Jackson, Annabeth Chase, Jason Grace, Piper McLean, Leo Valdez, and others. They must unite their unique powers, navigate treacherous quests, and form alliances with both gods and mythical creatures to prevent Gaea's rise to power and save the world from destruction.
