The Mark of Athena is the third installment of The Heroes of Olympus series. It was released on October 2, 2012. The book continues where The Son of Neptune left off, beginning shortly before The Son of Neptune ended, and is told from the points-of-view of Annabeth Chase, Leo Valdez, Piper McLean, and Percy Jackson. Annabeth Chase is amazed by the size of Camp Jupiter, which is twice the size of Camp Half-Blood, and notices the landmarks that Jason had told her about. She sees evidence of the Romans' recent battle, including the cracked dome of the Senate House.