What could be an interesting plot for a Harry Potter Hobbit crossover fanfic?

One interesting plot could be that the wizards from Harry Potter world accidentally stumble upon the Shire while on a magical experiment gone wrong. They meet the hobbits and learn about their simple yet fulfilling lives. Meanwhile, the hobbits are in awe of the magic the wizards possess. Then, an ancient evil that threatens both the wizarding world and Middle - earth emerges, forcing them to combine their strengths. The wizards use their powerful spells and the hobbits' courage and resourcefulness to fight against it.

One idea could be that the Hogwarts students go on an exchange program to Middle - earth. They could learn magic from the wizards there like Gandalf and in return teach them some of their own spells. Another could be that the One Ring somehow finds its way to Hogwarts and causes chaos among the students and teachers as they try to resist its power. Or perhaps a character like Harry Potter is transported to Middle - earth and has to use his skills to help the Fellowship in their quest.

Perhaps in the crossover, the Prototype virus could somehow infect the magical creatures in the Harry Potter universe. This would lead to a crisis where normal spells and magic can't stop the infected creatures. Harry and his friends would have to seek help from Mercer, who understands the virus. Together, they could try to find a way to either cure the infected or contain the spread. Mercer might use his own knowledge of the virus and his powers to fight the infected creatures, while Harry uses his magic skills to protect Mercer from magical attacks.

A possible plot is that a powerful magical artifact in the wizarding world is actually a key to an ancient Stargate on Earth that has been long forgotten. Harry and his friends, along with the Stargate team, embark on a quest to find this Stargate. Along the way, they face challenges from dark wizards who also want the artifact for their own evil purposes and the Goa'uld who sense the power of the artifact. They must work together, using both magic and technology, to reach the Stargate and unlock its secrets.

Maybe there's a prophecy in both worlds that foretells of a combined force from the wizarding world and the ninja world being the only way to defeat an ultimate evil. So, Naruto and Harry are brought together. They face challenges in understanding each other's cultures and powers at first. But as they train together, they find ways to merge their skills. For instance, Naruto's rasengan could be enhanced with a magical spell to create a more powerful attack.

One idea could be that a female Harry Potter somehow gets transported to Middle - earth from the wizarding world. She could use her magic skills to help the hobbits in their quest. Maybe she teaches them some simple spells for protection or to make their journey easier.

A possible plot is that Voldemort discovers the existence of the demigods and tries to use their powers for his own evil purposes. He sends his Death Eaters to capture some demigods. Percy and his friends manage to escape and seek refuge at Hogwarts. At Hogwarts, they learn about magic in a whole new way while also teaching the wizards and witches about their own powers. The two groups then have to combine their skills, like the demigods' combat abilities and the wizards' spell - casting, to fight against Voldemort and his new - found allies from the world of Greek mythology.

Well, perhaps there could be a situation where a character from True Blood, like Sookie Stackhouse, somehow ends up at Hogwarts. She has her telepathic abilities which could be really interesting in the wizarding world. The Hogwarts students might be both fascinated and a bit scared of her. And then, she could get involved in some sort of mystery that Harry Potter and his gang are also trying to solve. Maybe there's a dark magic that is affecting both the magical folk and the vampires, and they have to work together to stop it.

One idea could be that Voldemort discovers a way to enter the DC universe and teams up with some of the Justice League's villains like Lex Luthor. The Hogwarts students and the remaining members of the Justice League have to join forces to stop them. The wizards can use their magic while the superheroes use their powers.

One possible plot could be that the Death Eaters in the Harry Potter world team up with the Akatsuki from Naruto. Harry and his friends, along with Naruto and his comrades, have to join forces to stop this powerful alliance. They could learn from each other's magic and jutsu. For example, Naruto could teach the wizards about chakra control, and the wizards could show Naruto some advanced spells for defense and offense.