One plot idea could be that Bellatrix, in an alternate reality, has a change of heart and decides to protect Hermione from other dark forces. Maybe she sees a bit of herself in Hermione's fierce determination. Another could be that Hermione, while researching dark magic for a school project, accidentally stumbles upon a long - forgotten connection between her family and Bellatrix's, leading to a strange alliance. And a third idea might be that Bellatrix is cursed and Hermione is the only one who can break the curse, but in the process, they have to face their deep - seated prejudices about each other.
Well, perhaps there's a fanfiction where Sirius Black is wrongly accused again, but this time Hermione believes in his innocence from the start. She uses her intelligence and resources to prove his innocence while they are on the run from the Ministry. Along the way, they form a deep bond and discover new magical abilities within themselves that they use to clear Sirius' name and also make some changes to the wizarding world's justice system.
Well, perhaps in a fanfiction, Sirius Black could time - travel back to Hermione's school years. He'd be this mysterious figure who helps her with her studies in the Room of Requirement. Their relationship could develop as he shares his knowledge of the old wizarding ways, and they fall in love while trying to prevent some dark magic from resurfacing.
Another plot could involve Hermione using her intelligence to uncover secrets within Bellatrix's family history that have been hidden for generations. This could lead to a strange alliance between them as they both seek the truth. For example, Hermione might find out that there was a powerful magic in Bellatrix's family that could be used to defeat a new dark force emerging in the wizarding world.
A plot could involve the daughter using her unique position to bring about peace. Since she has a connection to both the 'good' side through Hermione and the 'dark' side via Bellatrix, she could be the key to bridging the gap between the two warring factions. For example, she might use her knowledge of both sides' secrets to negotiate a truce.
A plot could involve Hermione and Bellatrix both being Animagus and their forms having some sort of connection. For example, Hermione's Animagus form is a small, intelligent animal like an owl, while Bellatrix's was a large, powerful but dangerous bird like a raven. They unknowingly cross paths in their Animagus forms and some sort of magical bond or understanding starts to form between them. This could lead to a complex relationship where Hermione tries to use this connection to stop Bellatrix's evil deeds.
A plot could be about Hermione and Bellatrix having to work together to solve a mystery within the wizarding world. Maybe there's a dark magic object that is causing chaos, and their combined knowledge of magic, despite their differences, is needed to stop it.
One idea could be a time - travel plot where Hermione somehow gets sent back in time and has to deal with a younger Bellatrix. Maybe she tries to change Bellatrix's path to the dark side. Another could be a magical duel between Hermione and Bellatrix where Harry is caught in the middle, forced to choose which side to help. Or a plot where Bellatrix, under some sort of spell, has to team up with Hermione and Harry to fight a greater evil.
A plot could involve FemHarry having a special connection to an ancient magical artifact that Hermione helps her research. As they dig deeper, they find out it has the power to change the wizarding world. They then have to protect it from dark wizards who want to use it for evil. This would lead to a lot of action and suspense.
Well, a plot might be that Hermione is deaged due to a magical accident in the library. As a deaged Hermione, she has a different view on things. She might start to question the rules of Hogwarts more, as she doesn't have the same level of respect for them as her older self. Her friends, Harry and Ron, would have to deal with this new, more rebellious Hermione while also trying to figure out how to reverse the deaging spell. This could cause a lot of chaos in Hogwarts.
One plot idea could be Hermione helping Hagrid with a new magical creature he discovers. Maybe it's a creature that has unique abilities and Hermione uses her extensive knowledge from books to figure out how to take care of it.