The story begins with Jason waking up on a school bus with amnesia. He is sitting next to a girl holding his hand named Piper who says she is Jason's girlfriend, and a kid named Leo who says he is Jason's best friend. They are on a bus for kids who are trouble makers and problems to their parents and are taking a trip to the Grand Canyon. Once they arrive at the Grand Canyon they are attacked by kids on the bus who become storm spirits while they are crossing a bridge across the Grand Canyon and attack Jason and his group. The supervisor, Coach Hedge transforms into a satyr and defends the children from the storm spirits. While the satyr is fighting the storm spirits, Jason notices a coin in his pocket. Jason takes out the coin, which then it turns into a magical sword in which he begins to fight the storm spirits with Coach Hedge. As they defeat the spirits, during their flee they take Coach Hedge with them. As the storm spirits take away Coach Hedge a chariot with Annabeth in it who was searching for her lost boyfriend Percy Jackson. Annabeth came to look for him but was disappointed to realized he wasn't there. Annabeth then takes Jason,Piper, and Leo to a Camp called Camp Half Blood. At Camp Half Blood, they all realized they are demigods. Jason is the son of Zeus,God of the Sky, Piper is the daughter of Aphrodite,Goddess of Love/Beauty and Leo is the son of Hephaestus, God of the Forge and Fire. They powers which come with being a demigod have come to scare Leo and Piper as Piper always dreams a huge giant with her dad held hostage and she must betray her friends to save him or he will be eaten but her friends do not know about this and Leo is afraid because a fire is what killed his mother. Jason on the other hand doesn't remember his family, but he figures out that a person at the camp named Thalia is his sister. As the plot continues the groups is told by prophets that they need to rescue Hera, who is captured somewhere unknown. As the group is begin to ready for their journey, Leo remakes a robotic dragon named Festus, which was terrorizing the camp as it was a creation of one of Leo's brothers who could not control it. They use Festus to travel around the continent, from which they had many battles, including fights with cyclopes, Medea, King Midas, wolves and much more. Sometime during their travels they rescue Coach Hedge at the death of Festus. As the group travels on looking for more clues to try and rescue Hera, they get enough clues to figure out the Gaea, Goddess of Earth, is being reawakened, and has captured Hera. Gaea has captured Hera because she plans to destroy Hera, and use the energy created to summon the giant, Porphyrion. Piper comes and and tell Jason, Coach Hedge, and Leo that her father has been captured by a giant and they must try and save him. Coach Hedge realized the giant is Enceladus and they travel to go fight him. They defeat Enceladus and save Piper's Dad and give him a potion so he forgets everything that has happened to him by the mythical creatures. Coach Hedge takes back Piper's dad and the rest of the group heads on to save Hera. As they go to save Hera, they find Jason’s sister,Thalia, who was trying to stop the awakening of Gaea. They discover Gaea’s lair to find out Gaea is yet to be awakened and Porphyrion has not killed Hera yet. The group fights which leads to Hera being freed and Gaea not being awoken, but Porphyrion escapes. As they head back to Camp Half Blood, Leo begins to create a giant ship with the leftover parts of Festus to take them everywhere. Most importantly Jason has figured out that he is from a group of demigods which are Romen, rather than Greek. This is important because Roman and Greek demigods are separated because they always kill each other, but Hera is making them come together to destroy Gaea.