In Rick Riordan’s fantasy novel Percy Jackson and the Olympians: The Lightning Thief, Percy’s divine father is Poseidon.
Percy Jackson initially believes he is an ordinary boy with unusual difficulties at school. After reaching Camp Half-Blood, he learns that he is a demigod, the son of the Greek god Poseidon and the human Sally Jackson. Poseidon is associated with the sea, earthquakes, and horses.
Percy’s parentage explains several abilities shown in the novel, including his comfort underwater and his connection to water. His identity also makes him central to the conflict involving Zeus’s stolen master bolt.
A common mix-up is to name Zeus because the master bolt belongs to him and the Olympian dispute drives the plot. Zeus is Percy’s uncle, not his father. The novel is the first Percy Jackson book and introduces the modern setting of Camp Half-Blood.