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.
Well, in some versions, Fred might use his quick-witted magic skills. He could cast a distraction spell to draw Bellatrix's attention away from Hermione. Maybe a spell that creates multiple illusions of himself, confusing Bellatrix long enough for him to grab Hermione and disapparate them to safety.
One great Hermione and Fred werewolf fanfiction is 'Moonlit Encounters'. In this story, the werewolf element adds a new dimension to their relationship. The author beautifully weaves in the magical world's lore related to werewolves and shows how Hermione and Fred face the challenges together. It has some really interesting plot twists that keep you hooked.
In fanfiction, a Fred and Hermione secret relationship often adds an interesting twist. Writers might explore how their different personalities interact. Fred's humor and mischievous nature could contrast with Hermione's studious and rule - following side. It could start with a chance encounter in the Hogwarts corridors, leading to shared secrets and a growing bond that they keep hidden from their friends for various reasons, like fear of judgment or disrupting the group dynamic.
One common theme is the clash of personalities. Fred is often portrayed as more laid - back and mischievous while Hermione is studious and rule - abiding. So, their different approaches to situations often lead to fights.
Draco Malfoy could be a likely antagonist. He might be jealous of the friendship or whatever relationship is developing between Fred and Hermione and try to cause trouble for them. Another could be some of the more strict professors who don't approve of their unorthodox ways of doing things.
One common theme is miscommunication. Often, Fred or Hermione misinterprets the other's actions, leading to jealousy. For example, if Hermione is friendly with another male character, Fred might think she has romantic feelings for that person without actually talking to her about it.
Their relationship would likely become more serious and responsible. They'd have to put aside some of their youthful antics as they now have a child to think about, even if it's from the future. There would be a new level of trust and understanding as they work together to deal with the situation.
The combination of Hermione's intelligence and Fred's mischievous nature in a werewolf - themed story is really appealing. Hermione's logical thinking can be pitted against the wild and unpredictable werewolf aspect, and Fred's adventurous spirit adds to the excitement. It's a fresh take on their characters and gives a new perspective on their relationship.
I'm not sure if there are many fanfictions specifically with that plot. But you could try searching on big fanfiction platforms like Archive of Our Own. They have a vast collection, and you might be able to find something that comes close to this concept.