One possible plot could be that the Lestrange brothers initially see Hermione as a powerful witch they can use for their dark purposes. However, as the story unfolds, they might start to have complex feelings for her. Maybe they realize her value as a person beyond her magic and struggle with their own dark natures.
In a fanfiction, the Lestrange brothers could want Hermione because they believe she has knowledge that could help them revive some dark magic. But Hermione, being the intelligent and strong - willed witch she is, resists them. This could lead to a series of cat - and - mouse chases and battles of wits between them.
Well, it could involve the Lestrange brothers having some dark motives for kidnapping Hermione. Maybe they want to use her knowledge of magic for their own evil plans, like getting access to powerful spells she knows.
Perhaps the plot is centered around Hermione trying to reform the Lestrange brothers. She might see some good in them that others don't, and attempts to bring them over to the side of good. This could lead to all kinds of situations, like her having to protect them from the wrath of other wizards who don't trust them.
One possible plotline could be that the Lestrange brothers, who are initially on the side of the Dark Lord, have a change of heart due to their interactions with Hermione. Maybe they start to see the error of their ways and end up helping her in some way.
Hermione is known for her strong sense of justice and intelligence. The Lestrange brothers, coming from a dark pure - blood family, might have a more cavalier attitude towards the law and a different view on power. Hermione would clash with them when it comes to ethical use of magic. For example, she would never condone their use of dark spells for personal gain. Her studious nature would also contrast with their more impulsive and power - hungry ways.
One idea could be a story where Hermione has to work with the Lestrange brothers in a dangerous mission to retrieve a powerful magical artifact. They start off distrusting each other but as the mission progresses, they learn to rely on one another's skills. Another plot could be that Hermione discovers a long - hidden connection between her family and the Lestranges, which forces them to interact in unexpected ways. Maybe she has to use her intellect to prevent the brothers from falling back into their dark ways.
One idea could be that Hermione discovers a hidden connection between the Lestrange brothers and an ancient magic. Maybe she stumbles upon a secret library that was once in the possession of the Lestrange family, and the brothers are also after the knowledge there. They start as rivals but gradually form an unlikely alliance as they realize they need each other to unlock the secrets. Another plot could involve Hermione trying to redeem the Lestrange brothers. Since they come from a dark family background, she could use her intelligence and compassion to show them a different path. For example, she could introduce them to the idea of using magic for good in ways they had never considered before.
It's also possible that Hermione tries to reason with the Lestrange brothers. She could appeal to their better nature, if they have any left. Maybe she could remind them of the consequences of their actions, or try to make them see the error of their ways in following Voldemort. This could lead to an internal struggle within the brothers about whether to continue holding her or let her go.
One common theme might be power dynamics. Since Hermione is in a'slave' role, it would likely explore how the Lestrange brothers, who are associated with the Dark Arts, exert their power over her. Another theme could be Hermione's struggle for freedom and how she might resist or adapt to her situation.
One possible plotline could be that the Lestrange brothers use their dark magic and charm to gradually draw Hermione into their world. Maybe they start by showing her some dark secrets that she becomes intrigued by against her better judgment.
There are likely some out there. However, this kind of fanfiction often takes a rather dark and morally complex turn as the Lestrange brothers are Death Eaters in the original 'Harry Potter' lore. It might be hard to find ones that are well - written and don't cross into inappropriate territory.