One exciting plot twist could be that while running, they stumble upon a hidden passage that leads to a secret wizarding community that has been in hiding from the Ministry. This community has its own set of rules and magic that Fred and Hermione have to adapt to quickly.
Maybe they run into a magical creature that initially seems menacing but actually turns out to be a helpful ally. For example, a large, growling beast that scares Umbridge away and then guides Fred and Hermione to a safe place. In the fanfiction, this could add an element of mystery and danger as they first encounter the creature not knowing its true nature.
One common element is the use of magic in creative ways to evade Umbridge. For example, Fred might use his Weasley - brand magic items, and Hermione would rely on her extensive spell knowledge.
One popular fanfiction with this theme might be 'Escape from Umbridge's Tyranny' which details their thrilling escape and the challenges they face along the way. It has great character development and an exciting plot.
Hermione, on the other hand, could become more daring. She is already brave, but this situation could push her to take risks she normally wouldn't. She might be the one to suggest trying untested spells or taking paths that are less known in order to escape. As they run, she could learn to trust her instincts more and not just rely on book knowledge.
It could also be that they run away for a more personal reason. Maybe Fred has feelings for Hermione that go against the social norms in the wizarding community. They run away to be together and explore their relationship away from the prying eyes and judgmental attitudes of their friends and family.
One common plot twist could be that Fred actually isn't the father after all, and there's a big mystery about who the real father is. This can lead to a lot of drama and conflict.
One interesting plot twist could be that while in each other's bodies, they have to deal with the opposite gender's social expectations at Hogwarts. For example, Hermione in Fred's body might struggle with the more laid - back attitude towards studies in Gryffindor among the boys. Another could be that they accidentally use magic in a way that reveals their situation to a few select characters, like Ron, who then has to help them keep it a secret. And a third plot twist might be that they start to understand each other's personalities and insecurities better through this strange experience, which changes their relationship for the better in the long run.
One popular plot twist is when Hermione has to choose between Fred and her previous relationship with Ron. It adds a lot of drama to the story. Another is when Fred discovers a long - lost family secret that affects their marriage.
One possible plot twist could be that Snape saves Harry in a very public way, which shocks everyone in Hogwarts. Maybe Umbridge was about to use an illegal and extremely harmful spell on Harry during a public 'interrogation' session, and Snape steps in at the last moment, revealing some long - hidden information about Umbridge's true nature that even Dumbledore wasn't fully aware of.
A great plot twist could be that Umbridge is actually an undercover agent for the Order of the Phoenix all along. She has been playing the role of the villain to get closer to the Death Eaters at Hogwarts. Harry discovers this accidentally and has to work with her in secret to take down Voldemort's supporters in the school.
The Ministry of Magic itself could be an antagonist. If Fred and Hermione are running away because they've uncovered some sort of corruption or dark secret within the Ministry, the Ministry officials would want to stop them from spreading the truth.