A really cool plot could be that the traveler goes to a dimension where magic is fading away. They discover that it's because of an ancient curse. So, they embark on a journey to find the origin of the curse and a way to break it, all while interacting with alternate versions of the well - known Harry Potter characters.
A traveler could be from a different magical realm entirely and come to the Harry Potter universe. They bring with them unique magical abilities that both fascinate and frighten the wizards in the Harry Potter world. This could lead to a series of adventures where they either share their knowledge or are hunted down by those who fear the new magic they possess.
One idea could be that in the alternate dimension, Voldemort won the war and Hogwarts is now a dark and dreary place where students are taught only dark magic. Another could be that the wizarding world is merged with the Muggle world in a strange way, like there are magical creatures running amok in London streets. Or perhaps in this alternate dimension, Harry was sorted into Slytherin and has to deal with a whole different set of challenges and prejudices.
Well, perhaps in some 'Harry Potter dimension jumper fanfiction', there's a dimension where the Marauders are still alive and they team up with the modern characters to fight a new dark threat. Or a dimension where magic is dying out and the jumper has to find the source of the problem and fix it. This could involve traveling to different magical locations in that dimension, like the Forbidden Forest which might hold some secrets.
Well, a cool plot for 'Harry Potter in Another Dimension' fanfic could be that Harry discovers he has a twin in this other dimension. His twin has been raised by Voldemort and has a very different view of the wizarding world. Harry has to find a way to convince his twin to abandon Voldemort's ways. Or, what if in this dimension, the Sorting Hat can talk out loud all the time and gives very different sorting decisions? For example, it might put all the brave students in Slytherin and the cunning ones in Gryffindor. It would be really interesting to explore how the relationships between the houses change.
Another interesting aspect could be that in his personal dimension, Harry has a different set of friends. He might meet some students from other wizarding schools who are also in their own personal dimensions, and together they form a unique magical community.
One idea could be that in the alternate dimension, Voldemort won the war long ago. Hogwarts is now a dark and dreary place, with Death Eaters as teachers. Harry and his friends, who are part of an underground resistance, have to find a way to travel back in time to change the course of history.
Hermione is often a popular character. Her intelligence and resourcefulness make her a great asset in different dimensions. She can quickly adapt to new situations and figure out how the magic in that dimension works.
One possible interesting plot could be Harry finding a new magical dimension where the rules of magic are completely different. For example, instead of using wands, magic is controlled by thoughts alone. He has to learn these new ways quickly to face a dark threat that exists in this dimension which is planning to invade the wizarding world he knows.
A great plot for a Potter Manor fanfiction could involve a mystery that surrounds the manor. For instance, strange noises at night lead Harry to uncover a long - forgotten chamber. It could also be about Harry restoring the manor to its former glory, perhaps with the help of Hermione's research on ancient magic used in the construction of such manors.
One interesting plot idea could be exploring what would happen if Harry had a different upbringing, like being raised by the Malfoys. It would completely change his view of the wizarding world and his relationships. Another idea might be a time - travel fanfic where Harry goes back to the Marauders' era and interacts with his parents and their friends. This could lead to him preventing certain tragedies or changing the future in unexpected ways. And then there's the concept of a fanfic where the roles are reversed, and Voldemort is the one trying to protect the wizarding world from a greater evil, with Harry being the main antagonist.