Demigod Percy Jackson, still with no memory, and his new friends from Camp Jupiter, Hazel and Frank, go on a quest to free Death, but their bigger task is to unite the Greek and Roman camps so that the Prophecy of Seven can be fulfilled.

"The Greek and Roman demigods must simultaneously prevent the earth mother, Gaea, from waking and stop war from breaking out at Camp Half-Blood"-- Provided by publisher.

Jason, Piper, and Leo, three students from a school for "bad kids," find themselves at Camp Half-Blood, where they learn that they are demigods and begin a quest to free Hera, who has been imprisoned by Mother Earth herself. "Cuando Jason despierta, sabe que algo va muy mal. Está en un autobús camino de un campamento para chicos problemáticos. Y le acompañan Piper --una muchacha (bastante guapa, por cierto) que dice que es su novia y el que parece...

Greek and Roman demigods from the Prophecy of Seven must work together to seal the Doors of Death, and help Percy and Annabeth escape the Underworld in the process. Gaia, la madre tierra, se ha propuesto destruir el mundo de los mortales con sus tropas de monstruos y gigantes, y solo hay un modo de impedirlo: cerrar las Puertas de la Muerte, por donde estas criaturas están escapando de los infiernos. Y, lo más importante, hay que hacerlo desde...