One idea could be that Bella, instead of becoming a vampire, is bitten by a zombie. She then has to struggle with her new zombie nature while still holding onto her humanity. For example, she might try to resist the urge to attack her human friends like Jacob and Charlie.
One idea could be that Bella, with her unique ability to attract vampires in her original story, has an unexpected reaction to the zombies in The Walking Dead universe. Maybe her scent or some hidden power she has confuses the zombies, leading to some comical or strategic situations for her group.
Well, perhaps in the fanfiction, the SAS discovers a portal that leads to a different dimension full of zombie - like creatures but with unique abilities. They then have to use their military skills combined with the knowledge they gain from the new environment to survive and close the portal. They could encounter some local resistance fighters in that dimension who are also trying to fight the zombies, and they all join forces.
One idea could be that Bella and Hunter get into an argument over a football strategy, but then realize they both have the same goal of winning the big game and end up working together better than ever. Another could be a situation where they accidentally get locked in the school gym overnight and have to rely on each other to get out and also face their feelings for each other during that time. Or perhaps they both enter a local talent show separately and then decide to team up at the last minute to create an amazing performance.
One plot idea could be that Bella and Zach get into an argument over a football strategy, but then they realize they both have the same goal and end up working together better than ever. Another could be a situation where Zach gets injured and Bella has to step up to help him both in his recovery and on the football field. Maybe they also go on a double date with their friends and some comical misunderstandings occur during the date.
One idea could be a character from the Enclave finding themselves in a situation where they have to team up with a group from the Fallout world they usually oppose. Maybe a lone Enclave soldier gets separated from his unit and is forced to rely on a group of wastelanders to survive. This could lead to a lot of character development as he sees a different side of the world outside the Enclave's ideology.
One possible plot could be that a powerful necromancer from the Naruto world accidentally unleashes a zombie plague. Naruto and his friends have to not only fight their zombified comrades but also find a way to reverse the spell. They could use their ninja skills in unique ways, like using shadow clones to distract the zombies while they search for a cure.
One idea could be that Bella is a new nurse in the hospital and she discovers a secret patient who has a mysterious illness. She then teams up with a brilliant but reclusive doctor to try and solve the mystery.
A really interesting plot could be that Bella, as an enchantress, accidentally casts a spell on the whole town that makes everyone act out their deepest desires. This leads to chaos as people start behaving in strange and unexpected ways. Bella then has to find a way to reverse the spell while also dealing with the consequences of her actions and learning more about her powers in the process.
One plot idea could be that Bella is transported into the Cinderella story. She uses her modern - day knowledge to help Cinderella in a new way, like teaching her self - defense so she can stand up to her step - sisters. Another could be that Cinderella has some of Bella's traits, like being a bit clumsy at times but still having a heart of gold. A third idea is that Bella discovers that Cinderella's fairy godmother is actually a powerful witch from her own world, and they have to team up to defeat an evil force that threatens both of their worlds.
One idea could be that Sam and Bella discover a hidden magical realm together while on a hike in the forest. They have to work together to find their way out and in the process, they learn more about each other's fears and hopes.