One possible plot could be that Annabeth is under some kind of mind control. Maybe a powerful enemy has taken over her mind, forcing her to turn against Percy. Another could be a misunderstanding. For example, she might think Percy has betrayed her or their friends in some way, leading to a tragic confrontation.
One possible plot could be that Annabeth jumps on Percy out of excitement when they finally find a solution to a really difficult quest. For example, they've been searching for a way to defeat a powerful monster and when they figure it out, Annabeth's joy makes her jump on Percy.
In this type of fanfiction, it could be that Annabeth enslaves Percy as a form of protection. She may think that by controlling him, she can keep him out of more dangerous situations. However, this backfires as Percy begins to resent her for taking away his freedom. It could also be part of a complex relationship dynamic where misunderstandings and past traumas lead Annabeth to believe that enslaving Percy is the only way to keep their relationship intact, although this is a very twisted view.
One possible plot development could be that Annabeth is filled with guilt and remorse. She might isolate herself from the rest of the demigod community. For example, she could leave Camp Half - Blood and go on a self - imposed exile. She would constantly be haunted by memories of Percy and struggle to come to terms with what she has done.
She might be grateful. After all, if she has a fear or aversion to spiders, Percy getting rid of it is a kind gesture.
One possible plot could be that Percy makes a big mistake like getting involved with another girl out of misunderstanding or being forced into a situation that makes it seem like he's cheating on Annabeth. This would shatter Annabeth's trust and break her heart.
One interesting plot could be that Percy has to face an ancient and powerful Titan that has been awakened from a long slumber. He uses his unique water powers in unexpected ways, like creating a giant water vortex to trap the Titan and then using his sword to deliver the final blow. Maybe he also teams up with some unlikely allies, such as a group of minor gods who have a vendetta against the Titans.
No, it's not that common. Most fanfictions in the Percy Jackson fandom tend to focus on the positive relationships between the characters, like Percy and Annabeth's love story or the adventures of the demigods together. However, every now and then, some darker or more alternative takes like this one might pop up, but they are definitely in the minority.
One interesting plot could be a quest where Percy, Rachel, and Annabeth have to work together to retrieve a powerful artifact. They might face various monsters and challenges along the way, and there could be some tension between Annabeth and Rachel as they both have feelings for Percy.
One plot could be Percy seeing Annabeth spending a lot of time with another demigod on a quest. He gets jealous and starts acting strange around her. This could lead to some misunderstandings between them until they finally talk it out.
In some fanfictions, they could be studying in a magical library where the books come to life. This would add an element of adventure to their study sessions as they have to deal with the chaos caused by the animated books while still trying to study.