Well, there are different possibilities. One is that Hermione, while kidnapped, finds a way to turn some of Voldemort's followers against him. This leads to an internal conflict within Voldemort's ranks and ultimately her escape. Or perhaps there's a magical object or spell that Hermione discovers during her captivity that not only helps her get free but also weakens Voldemort significantly, leading to his downfall in the end of the fanfic.
In some fanfics, Hermione might outwit Voldemort on her own and escape. For example, she could use her knowledge of magic to break free from whatever bindings he has put on her and then find a way to get back to her friends. Another way it could end is that Voldemort, realizing Hermione's value as a hostage is diminishing, releases her for some self - serving reason, like trying to make a deal with the good side.
Often, it could end with Hermione being rescued. Maybe Harry and the others stage a big rescue mission and manage to defeat Voldemort in the process.
Another way it could end is with a bittersweet conclusion. Harry may sacrifice something, like a part of his magic or a relationship, in order to stop Voldemort from achieving his ultimate goal. This could be a more complex and thought - provoking ending, showing the cost of victory in the face of such great evil.
In a fanfic where Voldemort kidnaps Harry, it could lead to a lot of intense situations. Harry might be used as a bait to lure his friends into a trap. Or Voldemort could try to turn Harry to the dark side, using various forms of dark magic and psychological manipulation.
In some fanfictions, the focus could shift to Hermione's internal struggle. She might be forced to relive some of her worst memories or face her fears because of Voldemort's dark magic. However, this could also be the moment when she discovers new powers or strengths within herself that she didn't know she had, which she could then use to escape or fight back.
In some fanfictions, Hermione might use her wits to try and outsmart Voldemort. For example, she could pretend to be on his side while secretly planning an escape or a way to undermine his plans. She's very intelligent, so she could try to find a weakness in Voldemort's defenses or his followers.
One popular fanfic could be 'The Dark Lord's Captive' where Hermione is kidnapped by Voldemort and she uses her intelligence to outwit him in unexpected ways. Another might be 'Hermione in the Dark Lord's Lair' which focuses on her psychological struggle while being held captive.
Well, Harry might discover some hidden passageways in Voldemort's lair. Since he has a lot of experience with tricky situations at Hogwarts, he could use his wits to find a way out. Also, he could try to appeal to any shred of humanity left in Voldemort's followers, if there are any, and get them to help him escape.
The ending might also involve the power of friendship. Hermione's friends come to her aid when they discover the stalking. Together, they manage to expose Dolohov's actions to the wizarding world, leading to his banishment or imprisonment, and Hermione can finally live in peace.
Harry would probably become more conflicted. His views on good and evil would be severely tested. Hermione might become more cunning as she tries to outwit Voldemort while living under his roof. Voldemort himself might develop a strange sort of attachment to them, which could make his actions even more unpredictable.
A 'Harry and Voldemort married fanfic' might be about redemption. Voldemort could be redeemed through his relationship with Harry. The story could explore how Harry's love and positive influence gradually change Voldemort. For example, Voldemort might start to care about the well - being of others, and they could together fight against the dark forces that still exist in the wizarding world. This would be a very different take on their relationship compared to the original story.
Typically, in these fanfictions, Hermione's identity as Voldemort's daughter shakes up the whole wizarding world. It usually starts with her being the only one aware of this fact. As she tries to come to terms with it, she may start to have strange dreams or visions related to Voldemort's past. These could provide her with clues about his motives and the secrets of his dark magic. Her relationship with other characters changes drastically. Her friends might be initially distrustful, but as the story progresses, they come to see that Hermione is still the same person they knew. Meanwhile, Hermione might be on a quest to find out if there are any other family members she has on her father's side, which could lead to more adventures and revelations.