<P> The Mark of Athena is an American fantasy - adventure novel written by Rick Riordan, based on Greek and Roman mythology . It was published on October 2, 2012, and is the third book in The Heroes of Olympus series, a spin - off of the Percy Jackson & the Olympians series . It is preceded by The Son of Neptune and followed by The House of Hades . The novel has since been translated into many languages and released as a hardcover, e-book, audiobook and paperback . </P> <P> The story follows the Greek demigods Annabeth Chase, Leo Valdez, Piper McLean, and Percy Jackson; and the Roman demigods Jason Grace, Hazel Levesque, and Frank Zhang, finally uniting as prophesied in the "Prophecy of Seven". The novel is narrated in third - person, switching between the points of view of Annabeth, Percy, Piper, and Leo . </P> <P> The Mark of Athena received positive reviews from critics for its humor, characters, and mix of elements . Criticism was focused on its slow pace, action, and different perspectives . </P> <P> Six months after the events of The Lost Hero, Leo Valdez has constructed a flying trireme named Argo II, for use in the seven demigods' journey to Greece and Rome to stop Gaea from awakening . He, Jason Grace, Piper McLean, and Annabeth Chase, accompanied by Coach Hedge, arrive at Camp Jupiter to rendezvous with Percy Jackson and the Roman demigods Frank Zhang and Hazel Levesque . Annabeth, while having a talk with Camp Jupiter's praetor Reyna about the quest, reveals that in order to unite the Greek and Roman demigods against Gaea, they have to first retrieve the Athena Parthenos, a giant statue of Athena that was stolen by the Romans from the Greeks in ancient times and hidden somewhere in Rome . The statue can only be retrieved by the demigods of Athena through the help of the Mark of Athena, all of whom had died trying . However, an Eidolon sent by Gaea possesses Leo and forces him to fire a blast on the camp, inciting the paranoid augur, Octavian, to convince the Romans that the Greeks are a threat and have to be destroyed . </P>

Where does the mark of athena take place