The Blood of Olympus

In the breathtaking fifth and final book in Rick Riordan's #1 best-selling Heroes of Olympus series, the Greek and Roman demigods must simultaneously prevent Gaea from waking and stop war from breaking out at Camp Half-Blood. Though the Greek and Roman crewmembers of the Argo II have made progress in their many quests, they still seem no closer to defeating the earth mother, Gaea.