This was one of the best books I've ever read! It is about three demigods named Percy Jackson (returning from previous series by Rick Riordan and a son of Poseidon/Neptune), Frank Zhang, and Hazel Levesque. Percy's memories have been stolen by the goddess Juno. Therefore, Percy does not remember anything about Camp Half-Blood. Instead, Juno has sent him to a Roman camp for demigods, known as Camp Jupiter, which is led by a praetor known as Reyna. Before long, Percy, along with Frank (who is a son of the god Mars) and Hazel (who is a daughter of Pluto) is forced to go on a quest to save the camp from the giant Polybotes and his invading army, and to do that, the trio must go to Alaska, a.k.a. the Land Beyond the Gods, to save the camp's golden eagle, which has been stolen by the giant Alcyoneus. This eagle has magical powers and is charged with the power of the gods. Somewhere into the quest, Percy regains his memory due to the healing effects of gorgon's blood. Frank's life depends on a burnt piece of wood, and Hazel is supposed to be dead. Both of these half-bloods have hidden powers. Hazel can summon valuable stones from the ground, and Frank has some techniques that you can figure out by reading the novel. What makes the quest even harder for the three demigods is the fact that Thanatos, the "keeper" of death, has been captured by Alcyoneus, so monsters reform more quickly. The trio meets many obstacles along the way. They must befriend the Amazons (female warriors) and their queen, Hylla, who is Reyna's sister. They obtain a horse named Arion, who is the fastest creature on land and sea, from the Amazons. Percy must risk his life in order to gamble with a future-seeing escapee from the underworld who is named Phineas using gorgon's blood. At the beginning of the novel, the trio defeats two gorgons, and what was left was two identical vials of gorgon's blood. Blood from the right arm of a gorgon cures any disease, while blood from a gorgon's left arm kills instantly. The trio had to face several man-eating, cannonball-throwing ogres called Laistrygonians, who wanted to eat Frank. Every once in a while, Hazel has a flashback about her old life (in the 1940's). These flashbacks finally stop when Hazel experiences a flashback with Frank. Frank, on the other hand, has a magical piece of firewood that can burst into flames when he wants it to. This wood is tied to Frank's life force, and he will die when the entire piece of wood burns away. Percy completely remembers everything near the end of the book, and Gaea expects to use Percy as a "pawn" to bring the downfall of the gods. This novel also has several riddles and confusing prophecies in it. Ella the harpy, who is saved from Phineas, recites part of a prophecy inside Frank's family mansion's attic during the battle against the Laistrygonians: "To the North, beyond the gods, lies the legion's crown, falling from ice, the son of Neptune shall drown." Later, Ella says: "Wisdom's daughter walks alone, the Mark of Athena burns through Rome." Finally, Frank releases Thanatos in Alaska, and the trio returns to Camp Jupiter after defeating Alcyoneus in Canada (Alcyoneus is invincible in his birthplace[he was reborn in Alaska]) and retrieving the eagle and a chariot load of Imperial gold weapons, which can kill monsters. After Thanatos had been released, the dead stayed dead and, with the power of the golden eagle, the camp defeated the monster army. Finally, Percy faced off against Polybotes, defeated, and became the second praetor of Camp Jupiter (everyone wanted him to). At the very end of the book, the Greek airship appears in the sky overhead, with some of Percy's friends from Camp Half-Blood, and a few new demigods who are part of the second Great Prophecy. I would strongly recommend this book to people who have read The Lost Hero, and to people who have read the Percy Jackson series.