One idea could be that Percy and Jason have to team up to save a group of demigods who are trapped in an ancient, cursed maze. They use their combined powers of water and lightning to break through the various obstacles. Another could be a story where they swap powers for a day and have to deal with the consequences. For example, Percy tries to control lightning but accidentally zaps some of their friends' hair into crazy styles, while Jason struggles to keep the water from going wild when he tries to use Percy's power.
One plot idea could be Percy and Thalia going on a quest together to find a lost artifact that has the power to save their camp from a new threat. Another could be them getting into an argument over how to handle a new demigod at camp, which tests their friendship but ultimately makes it stronger. Maybe they could also travel to a different realm together where they have to rely on each other completely to survive and get back home.
One idea could be that Percy and Leo team up to build a super - cool underwater vehicle using Leo's mechanical skills and Percy's knowledge of the sea. Another could be them going on a quest to find a lost artifact that has powers related to both fire and water. They could face challenges like sea monsters and mechanical traps along the way.
One plot idea could be that Percy and Jason discover they are twins in a very unexpected way. Maybe during a quest, they start having the same strange dreams and realize they have a deeper connection. Another could be that they have to team up against a powerful enemy who is specifically targeting them because of their unique twin bond.
One idea could be a time - travel plot where Percy and Jason are sent back to the founding of Camp Half - Blood. They have to work together to ensure the camp is established correctly while also dealing with the ancient monsters and gods that were around at that time. Another could be a story where they swap powers for a day and have to learn to adapt to each other's abilities in the middle of a big battle against a new powerful enemy. A third idea is that they are stranded on a mysterious island together and must rely on each other's skills and knowledge to survive and find a way back home.
One idea could be that they team up to face a new and powerful monster that neither of them could defeat alone. Maybe it's a hybrid of a Greek and Roman mythical beast.
One idea could be a quest where Percy, Jason and Piper have to team up to find a lost artifact that has the power to control the elements. They face various mythical creatures along the way and have to use their combined powers to overcome obstacles.
Perhaps they go on a quest to find their long - lost family heritage. Along the way, they face various challenges that test their brotherly bond. They might have to cross a dangerous river that only Percy can navigate, but Jason has to use his wind powers to keep them from being swept away, while Nico uses his underworld powers to fend off the ghosts that lurk in the water.
One idea could be Jason and Percy having to team up for a special quest that no one else can handle. Maybe they have to retrieve a powerful artifact hidden deep in a dangerous realm. They start off not getting along well because of their different leadership styles, but as the quest progresses, they learn to respect each other and combine their powers in unique ways to overcome obstacles.
They could get lost in an old, abandoned part of the railway. Thomas might be a bit scared at first, but Percy stays calm. Together, they explore the area, find old railway artifacts, and then figure out a way to get back to their normal tracks. It would be a story of discovery and courage.
Another plot could involve Percy's friends getting accidentally transported to a different realm in the Percy Jackson universe. They have to rely on their friendship and the skills they've learned from Percy to survive and find their way back. For example, they might end up in the Underworld and have to navigate past various challenges without Percy at first.