Perhaps it's about creating a sense of drama and high - stakes. Torture is a very extreme and emotional situation. By putting Hermione in this position, the author can draw out strong emotions from the readers. It could also be related to character development. Hermione is often seen as a strong and intelligent character. Through torture, the author might want to show her vulnerability and how she overcomes it, while also showing Ron's role in that process.
I'm not a big fan of such dark fanfictions, but you could try looking on fanfiction.net. They have a large collection of Harry Potter fanfictions, and you might be able to find one with that plot there.
One reason could be Snape's sense of justice. Despite his often - cold exterior, he may not tolerate Ron's unjust behavior towards Hermione. Another reason might be that he sees something in Hermione that he values, like her intelligence or her thirst for knowledge, and doesn't want it to be extinguished by Ron's actions.
Fred could use his knowledge of the Weasley family's magic tricks and inventions. He might have some secret gadget or spell that can break through the barriers or spells that are being used to torture Hermione.
Hermione would likely be very angry at first. She is a strong - willed character and being kidnapped would go against all her principles of freedom and rights. She would probably try to reason with Ron immediately, using her logical arguments to make him see how wrong his actions are.
One possible motivation could be that Draco has changed. He might have seen the error of his ways and decided to do the right thing. Another motivation could be that he has feelings for Hermione, even if they are not fully realized yet. He doesn't want to see her in a bad situation, so he steps in.
Another reason is that Harry might see the bigger picture. He knows that the three of them are a team and that internal strife can be dangerous, especially in the magical world they live in. By protecting Hermione from Ron, he's trying to keep their group intact. He might think that if Ron's negative behavior towards Hermione is left unchecked, it could lead to the breakdown of their friendship and their ability to face challenges together.
It could be due to a misunderstanding. Ron might misinterpret Hermione's relationship with Draco. He could think there's something going on between them, especially in fanfiction where the Dramione pairing is the end goal. So, in his jealousy or anger, he decides to leave Hermione while she's pregnant without really understanding the situation.
One motivation could be for the sake of adventure. In fanfiction, Hermione might want to explore parts of the wizarding world that are off - limits to girls. By disguising as a boy, she gets the chance to do so.
It could be that the fanfiction depicts Ron in a negative light that Hermione doesn't agree with. She has a complex relationship with Ron, and while they may have their differences, she doesn't like to see him misrepresented. If the fanfic makes Ron look like a fool or a jerk in a way that doesn't seem fair or true to the original character, Hermione would likely be disgusted.
The relationship could deepen in a way that they rely on each other more. Hermione would need Ron's physical and emotional support during her pregnancy. Ron, on the other hand, would depend on Hermione's intelligence to make sure everything is going well. They might also have a stronger bond because they are creating a new life together. There could be moments of pure joy when they feel the baby move or when they start preparing the nursery, which would strengthen their love for each other.