In the house of Hades Percy and Annabeth escaped Tartarus. Nico and Jason visit Cupid. Frank becomes a Roman Praetor. Leo meets and falls in love with Calypso. Hazel learns to control the mist. The young demigods have to make it to Athens before August first, in fourteen days. Will they be able to stop Gaea or will demigod and Olympian blood flow through the streets of Olympus.