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 will have to cooperate in order to defeat the giants released by the Earth Mother, Gaea. Then they will have to sail together to the ancient land--Greece itself--to find the Doors of Death"--

"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"--

"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.

In their first encounter, demigod Percy Jackson and magician Carter Kane had to battle a giant crocodile on Long Island. A month later, Annabeth Chase ran into Carter's sister, Sadie, on the A train to Rockaway, where the pair fought a god named Serapis. Now trouble is brewing again, this time on Governor's Island. An ancient Egyptian magician named Setne has come back from the dead and is experimenting with Egyptian and Greek magic, trying to become...

"In response to an awful camp orientation video created by the god Apollo, Percy Jackson and other residents of Camp Half-Blood answer campers' questions such as 'What is this place?' and 'Do I get to keep the T-shirt?'"--

In The Son of Neptune, Percy, Hazel, and Frank met in Camp Jupiter, the Roman equivalent of Camp Half-Blood, and traveled to the land beyond the gods to complete a dangerous quest. The third book in the Heroes of Olympus series will unite them with Jason, Piper, and Leo. But they number only six--who will complete the Prophecy of Seven? With old friends and new friends joining forces, a marvelous ship, fearsome foes, and an exotic setting, The Mark...