While the Greek and Roman members of the Argo II crew have made progress in their various quests, they still do not seem ready to defeat Mother Earth, Gaia. Its giants have risen – all of them, and they are stronger than ever. They must be stopped before the Feast of Spes, the time when Gaia planned to sacrifice two demigods in Athens. She needs their blood – the blood of Olympus – in order to wake up. The demigods have more and more visions of a terrible battle at Camp Half-Blood. The Roman legion at Camp Jupiter, led by Octavian, is almost within firing distance. Although it is tempting to mistake the Athena Parthenos in Athens as a secret weapon, the friends know that the enormous statue must return to Long Island, where it could perhaps end a war between the two sides. The Athena Parthenos will go west; the Argo II will go east. The Gods, still suffering from multiple personality disorder, are useless. How can a handful of demigods hope to persevere against Gaia's army of powerful giants? Even though it is dangerous to head towards Athens, they have no other option. They have already sacrificed too much. And if Gaia wakes up, it's the end of the game.