The Lightning Thief is the first book in the series and was released on July 1, 2005.
After returning home from his boarding school for the summer, Percy and his mother, Sally Jackson, travel to their cabin in Montauk. However, the trip is cut short and after a series of harrowing incidents such as being attacked by a minotaur, Percy finds himself at Camp Half-Blood, a training camp for demigods like him. He discovers that he is a demigod son ofPoseidon, the Greek god of the sea & earthquakes, his best friend Grover is a satyr and the Greek gods are accusing him of having stolen Zeus' master lightning bolt. To clear his name and save the world from another war between the Olympian gods, he sets out to retrieve the lightning bolt from Hades, who they believe is the real thief. Thus Percy Jackson and his companions, Grover Underwood and Annabeth Chase, a daughter of Athena, start on a journey to the underworld, facing numerous mythological monsters on the way. After confronting an innocent Hades, they learn that their friend Luke Castellan, son of Hermes, is the real thief who stole the bolt to allow Kronos, the defeated king of the Titans, a chance to rise again.
The book was adapted into a film by Chris Columbus and 20th Century Fox, under the title Percy Jackson & the Olympians: The Lightning Thief, and was released on February 12, 2010.