Author Rick Riordan, all hard back books.
Ages 10+, Greek Mythology and Fiction/Adventure
Percy Jackson and the Olympian Series Book 1: The Lightening Thief (2005)
"Twelve-year-old Percy Jackson is on the most dangerous quest of his life. With the help of a satyr and a daughter of Athena, Percy must journey across the United States to catch a thief who has stolen the original weapon of mass destruction — Zeus’ master bolt. Along the way, he must face a host of mythological enemies determined to stop him. Most of all, he must come to terms with a father he has never known, and an Oracle that has warned him of betrayal by a friend." (Rickriordan.com)
Percy Jackson and the Olympian Series Book 4: The Battle of the Labyrinth (2008)