The Heroes of Olympus set includes all five books by Rick Riordan, each in paperback and hardcover formats. Published by Hyperion Books for Children, these fantasy novels are targeted towards young adults and ages 9-12. The stories follow the adventures of characters in a captivating narrative filled with magic and mythology, making them perfect for young readers who enjoy immersive and imaginative tales. With an engaging plot and relatable characters, this series is sure to entertain and inspire readers to explore the world of fantasy and adventure.