Another plot could be that Jackson is chasing a group of shadowy villains who are trying to release an ancient evil. He teams up with some unlikely allies during the chase and they all have to use their unique skills to stop the villains.
One idea could be a crossover where Percy and Magnus have to team up to defeat a common enemy that threatens both their worlds. Maybe a primordial being that can disrupt the balance of both the Greek and Norse mythologies.
A really cool plot could be that there's a prophecy that involves both of them. The prophecy says that only by combining their unique abilities - Percy's control over water and Magnus's connection to the Norse gods - can they save both the Greek and Norse mythologies from being wiped out by a new, unknown force. They have to go on a journey, meet various characters from both mythologies, and overcome many challenges along the way.
One idea could be a quest where Magnus and Percy have to team up. Maybe there's a new threat that combines the Norse and Greek mythologies, like a monster that has the powers of both a Greek hydra and a Norse dragon. They would have to use their different skills and knowledge to defeat it.
One idea could be that Jackson discovers a hidden magic in his diary that transports him to a different dimension every time he writes in it. Another could be that the diary holds the secrets of his family's past and he has to solve a mystery to unlock them. Maybe the diary has a sentient entity inside that only he can communicate with and it helps him with his daily life problems.
One idea could be that Skye and Chase have to work together to rescue a lost pup in a mysterious, fog - covered forest. They face various obstacles like quicksand and fallen trees. Another plot could be a race between them that turns into a team - up when they discover a villain trying to steal all the pup treats in Adventure Bay.
One idea could be exploring Magnus's relationship with his newfound powers in more depth. Maybe he discovers a new aspect of his abilities that was previously unknown. Another could be a crossover with other Norse mythology - related stories or characters.
One idea could be that the Jackson twins have a secret power that they discover together. They then have to keep it hidden from the world while also trying to figure out how to use it for good.
A great plot could be that the children are sent on a quest to a new, mysterious location that was previously unknown in the Percy Jackson universe. They might have to deal with strange new monsters and make allies among the local mythical beings. For example, they could end up in a hidden valley where the spirits of nature are at war, and they have to figure out how to restore balance. This would involve them using their powers in new and creative ways, just like their parents did in the original series.
A plot could be that Sally Jackson plants a lemon tree in her garden that turns out to be a gift from a minor goddess. The lemons from this tree have the power to give those who eat them the ability to see through illusions for a short time. Percy uses these lemons to his advantage when he is on a mission to retrieve a powerful artifact that is guarded by a monster that uses illusions to protect it.
One idea could be that Chase and Skye go on a special mission together where they get lost in an uncharted area. They have to rely on each other more than ever to find their way back. Maybe there's a mysterious force that's causing all their tech to malfunction, so they have to use their natural instincts and teamwork.