In his Percy Jackson and the Olympians series, Rick Riordan uses a combination of contemporary narration, humor, and updated tales to bring Greek myth to a modern-day young audience. The series follows protagonist Percy Jackson (a demigod son of Poseidon) through his years training at Camp Half-Blood (a summer camp for half-human children of the Greek gods) along with friends Annabeth Chase (daughter of Athena), satyr Grover Underwood, and many others. The main series consists of five books (The Lightning Thief, The Sea of Monsters, The Titan’s Curse, The Battle of the Labyrinth, The Last Olympian), in which Percy and his friends face modernized challenges from the Greek myths (such as Amazon warriors who work at a shipping warehouse for the website of the same name) as they try to stop Kronos from rising from Tartarus to destroy the world. Riordan’s Percy Jackson universe is populated by figures from Greek myth, including the 12 Olympian gods, other key immortals (such as Elder Centaur Chiron—activities director at Camp Half-Blood), and famous monsters, such as Cerberus (the Underworld’s three-headed guard dog) and the Gorgon Medusa.