A possible plot could be that Voldemort kidnaps Hermione because he realizes she has a unique understanding of ancient magic. He hopes to use her to unlock the secrets of magic that could make him even more powerful. Hermione, on the other hand, uses her time in captivity to study the dark magic around her, looking for a way to turn it against Voldemort. She also tries to leave hidden clues for her friends to find her.
In one possible plot, Voldemort might kidnap Hermione to use her knowledge of magic against Harry. He could try to force her to reveal secrets about Dumbledore's plans or the location of certain powerful magical artifacts. Hermione, being strong - willed, would resist and try to outwit Voldemort using her intelligence.
She would be terrified at first, but quickly gather her wits. Hermione is very intelligent, so she would likely start observing her surroundings, looking for any possible means of escape or a way to send a signal to her friends.
A really interesting plot twist might be that Voldemort is being controlled by an even darker force, and Harry has to figure out a way to break that control while being held captive. Or perhaps Harry's friends, thinking he is dead, accidentally start a chain of events that end up helping Harry escape in a very unexpected way. For example, Hermione might cast a spell that was supposed to be for protection but ends up creating a portal right in Voldemort's lair.
In some fanfictions with this concept, one key plot point could be Hermione's struggle to resist Voldemort's control while secretly trying to undermine his plans. For example, she might use her intelligence to mislead the Death Eaters. Another point could be the internal conflict she faces between her loyalty to her friends and the need to survive in this dark situation. And sometimes, there could be a sub - plot about her trying to find a way to break the enslavement spell or curse that binds her to Voldemort.
One possible plot could be that Dumbledore has been possessed by a dark entity. Under its influence, he kidnaps Hermione thinking she has some knowledge or power that the entity wants. Hermione then has to use her wits to try and break Dumbledore free from the possession while also trying to escape.
There could be. Fanfiction writers love to explore different scenarios that deviate from the original story. But it's important to note that this goes against the general perception of Dumbledore's character. In the official Harry Potter series, Dumbledore is a protector, not a kidnapper. But in the world of fanfiction, anything is possible.
Maybe it's her intelligence. Hermione is extremely smart and could use her knowledge in unexpected and intimidating ways that Voldemort, with his more brute - force and dark - magic - based approach, might not anticipate. For example, she could outwit him strategically in a battle of wits rather than relying on raw power like Voldemort does.
One possible plot could be that they are forced to join Voldemort under some sort of dark magic compulsion. Maybe Voldemort has a new powerful spell that he uses on them to make them his servants. Then they have to struggle with their own moral compasses while doing his bidding, and secretly try to find a way to break free and defeat him from the inside.
A plot could be centered around a prophecy that involves both Hermione and the Voldemort family. This prophecy might state that only Hermione can bring about the end of the dark legacy of the Voldemort family. So, she embarks on a journey to find out more about their history and secrets. Along the way, she has to face many challenges and dark magic that the family has left behind. She might also encounter descendants of the Voldemort family who are not entirely evil and are trying to break free from the dark reputation of their family name.
One interesting plot twist could be Hermione struggling with her dark heritage while trying to uphold her Gryffindor values. Maybe she discovers a hidden power within her that she initially fears is evil but later uses for good.
One common plot twist is that Hermione discovers her heritage at a crucial moment, like when she's about to be attacked by Death Eaters and suddenly some hidden power related to her being Voldemort's heir emerges. Another is that she has to struggle with the moral implications of being related to such an evil figure.