'Percy Jackson and the Olympians' is returning to Disney+ for a second season. The streaming service renewed the series that's based on the best-selling novels of the same name by author Rick Riordan a week after the show's first season concluded. Season two will adapt the second book of the novel series, 'The Sea of Monsters,' which sends Percy and some of his fellow demigods on an oceanic quest to retrieve the Golden Fleece.