Percy Jackson & the Olympians is a fantasy novel series by Rick Riordan. The series is set in the 21st century and features the Greek gods. The series is inspired by ancient Greek mythology, including the stories of Hercules and Theseus. The series follows Percy, a troubled tween with unexplainable powers. The series follows Percy, a troubled tween with unexplainable powers. Percy must journey across the United States to catch a thief who has stolen Zeus' master bolt. 