The Lost Hero is a fantasy-adventure novel by Rick Riordan, published in 2010. It is the first book in the Heroes of Olympus series, which is a sequel to the Percy Jackson & the Olympians series. The book is based on Greek and Roman mythology. * The story is about Jason, who wakes up on a school bus with a girl holding his hand. He has no memory of anything before waking up, except that something is wrong.