A teenager discovers he's the descendant of a Greek god and sets out on an adventure to settle an on-going battle between the gods.
Percy Jackson, like any teenager, has issues: on top of having ADHD, he also has to cope with an abusive stepfather and dysfunctional home life. When he realises that he is a demigod and his biological father is Poseidon, the sea god, he sets out to prevent all-out war between the Olympians after the lightning bolt of Zeus is stolen, and he is framed for it.—Tom Daly
Accused of stealing Zeus's powerful lightning bolt, Poseidon's son faces the threat of an all-out war among gods unless he returns the destructive weapon within two weeks. In the meantime, as war brews over Mount Olympus, unusual teenager Percy Jackson finds himself caught between two worlds, struggling to understand. But can a mere mortal prevent the impending battle, retrieve the bolt, and find the audacious lightning thief before the ancient deities destroy the Earth?—Nick Riganas
It's the 21st century, but the gods of Mount Olympus and assorted monsters have walked out of the pages of high school student Percy Jackson's Greek mythology texts and into his life. And they're not happy: Zeus's lightning bolt has been stolen. As Percy finds himself caught between angry and battling gods, he and his friends embark on a cross-country adventure to catch the true lightning thief and unravel a mystery more powerful than the gods themselves.—20th Century Fox
At the top of the Empire State Building, Zeus (Sean Bean) (god of the sky, thunder, lightning, king of the twelve gods of Mount Olympus) meets Poseidon (Kevin McKidd) (Percy's father, god of the seas, earthquakes, and horses), accusing Poseidon's demigod son, Percy Jackson (Logan Lerman), of stealing Zeus' master lightning bolt. Poseidon reminds his brother that Percy is unaware of his true identity, but Zeus declares that unless the bolt is returned to Mount Olympus before midnight of the Summer Solstice, in two weeks, war will be waged between all the gods.
Sixteen-year-old Percy struggles with dyslexia and ADHD but has a unique ability to stay underwater. On a school trip, Percy is attacked by Alecto (Maria Olsen), a Fury masquerading as his substitute English teacher, who demands the lightning bolt. Percy's best friend Grover Underwood (Brandon T. Jackson) (Percy's protector, a satyr) and his Latin teacher Mr. Brunner (Pierce Brosnan) (a centaur who trains heroes at Camp Half-Blood, the immortal son of Kronos and brother of Zeus, Poseidon, Hades, Demeter, and Hera) help scare off Alecto. Mr. Brunner gives Percy a pen which he claims is a powerful weapon and instructs Grover to take Percy and his mother Sally (Catherine Keener) to Camp Half-Blood - a hidden summer camp for demigod children on Long Island. There, they are attacked by the Minotaur, who seemingly kills Percy's mother. Percy discovers that Mr. Brunner's pen is a magical sword, and uses to fight off the Minotaur, killing it with its own horn.
Waking up three days later, Percy learns he is the son of Poseidon (His Dyslexia is because his brain is hardwired to read ancient Greek and not English, His ADHD is because he is buzzing with energy with a bias for action), Grover is a satyr (a half goat) and Percy's protector, and "Mr. Brunner" is Chiron, a centaur. Chiron explains how Sally married Percy's obnoxious stepfather, so that his scent could hide Percy's blood smell from anything that Zeus and Hades sent to kill him. Chiron warns that if the bolt is not returned, a war would start, Olympians would take sides and Earth would be the battleground, causing immense damage to billions. Chiron wants Percy to train so he can survive the world outside the camp and find the bolt.
Percy begins training in his demigod powers, which include water manipulation and healing, and meets other demigods, including Annabeth Chase (Alexandra Daddario), daughter of Athena (goddess of crafts, domestic arts, strategic warfare, peace and wisdom); and Camp Leader Luke Castellan (Jake Abel), son of Hermes (A Shepard God). Percy is visited by an apparition of Hades (Steve Coogan) (Percy's Uncle, God of the Underworld, the dead, and riches), who reveals the Minotaur abducted Sally to the Underworld to trade for the lightning bolt.
Defying Chiron's orders (Chiron wants Percy to ignore Hades and instead travel to Olympus to bargain with Zeus and convince him of his innocence), Percy sets out for the Underworld with Grover and Annabeth. Luke (Luke's dad is a messenger of the Gods and goes in and out of the Underworld all the time) gives Percy a map with the location of three green pearls belonging to Hades' wife, Persephone (Rosario Dawson) (goddess of springtime) (Hades has kept her prisoner in the underworld. So, she has secret visitors who use her pearls to get out of the underworld), which will allow them to escape the Underworld. Percy is also given a pair of flying winged shoes stolen from Hermes (Dylan Neal) (god of trade, thieves, travelers, sports, athletes, and messenger of the gods of Mount Olympus), and Luke's favorite shield.
At a garden center in New Jersey, with a help from Grover and Annabeth, Percy manage to decapitate Medusa (Uma Thurman) (a gorgon cursed by Athena) and takes the first pearl from her corpse. At the Parthenon in Nashville, Percy uses the shoes to retrieve the second pearl from the crown of the statue of Athena there, and Grover kills a Hydra with Medusa's head. The trio arrive at the Lotus Hotel and Casino in Las Vegas to obtain the third pearl; however, they forget their mission after eating lotus flowers. Those who eat the lotus flowers are isolated from the outside world and lose sense of time, a reference to the Lotus-Eaters. Percy snaps out from the spell of the lotus flower after hearing the voice of his father, Poseidon, through telepathy telling him not to eat any more flowers. Percy frees Grover and Annabeth from the flowers' effects; they locate the final pearl in the casino and escape the hotel. Annabeth realizes that they only have one day left to prevent the gods' war, as they were in the casino for five days. With all three pearls, Percy, Grover, and Annabeth enter the portal to the Underworld.
In the Underworld (after paying the ferryman in drachmas to ferry them across to Hades's palace), Hades finds the lightning bolt hidden inside Luke's shield (Hades needs the bolt to defeat his brothers and get out of the Underworld), revealing that Luke was the thief all along. Hades tries to kill the trio, but Persephone turns on him in retaliation for imprisoning her and gives the bolt to Percy. As they only have three pearls, Grover remains behind, while Percy, Annabeth, and Sally Teleport to the Empire State Building, the entrance to Mount Olympus. However, before they can enter, they are ambushed by Luke, who reveals that he stole the bolt to demolish Mount Olympus and establish the demigods as new rulers of Western civilization. After a battle across Manhattan, Percy seemingly kills Luke, returns the lightning bolt to Zeus, and reconciles with his father Poseidon.
Having been reunited with Grover, Percy and Annabeth continue to train.In a mid-credits scene, Sally kicks her abusive husband, Gabe Ugliano, out of her apartment. He returns to get a beer and, upon opening the refrigerator, is turned to stone by Medusa's head.
