Another plotline could be that a jealous demigod, who has some minor powers of persuasion that they've developed into a form of hypnosis, targets Annabeth out of envy. This demigod wants to make Annabeth look bad in front of Percy and the others. Percy, being in love with Annabeth, quickly realizes something is wrong and sets out to find the source of the hypnosis and free Annabeth from its control. Along the way, he has to deal with the challenges of the hypnosis - affected Annabeth's actions.
One possible plotline could be that a new villain, who has powers of hypnosis, targets Annabeth because of her strategic mind. The villain wants to use her knowledge of Camp Half - Blood and the demigod world to their advantage. Percy and the others then have to figure out how to break the hypnosis and stop the villain before it's too late.
Perhaps Annabeth is wrongly accused of a crime and is made a slave as punishment. Her friends, including Percy, try to prove her innocence while also dealing with the internal politics of the demigod society that allows such a cruel situation to exist. This could involve a lot of character development for all involved as they question the fairness of their world's laws and norms.
Perhaps in this fanfiction, a villain has somehow transferred Percy's power of hypnosis to himself and uses it on Annabeth to get information from her. Percy then has to race against time to break the hypnosis and save Annabeth, all while facing various challenges and obstacles set by the villain.
One plotline could be that they face danger from an old enemy who sees the unborn child as a threat. So they have to protect themselves and the baby. Another could be that Annabeth has some premonitions about the baby's future and they embark on a quest to understand what it means.
Another plotline could be centered around Annabeth's jealousy when other characters show interest in Percy. So she's constantly thinking about Percy and how much she wants him all to herself. Her 'drooling' over him is a sign of her deep - seated feelings that she might not fully express outwardly all the time.
Another plotline could be that they are babysitting a group of demigod toddlers at Camp Half - Blood. The toddlers keep getting into mischief, like stealing nectar and ambrosia. Percy and Annabeth have to keep them in line, teach them about the rules, and also make sure they don't accidentally harm themselves with their budding powers. It could be a really cute and chaotic story.
One scenario could be that Percy has some sort of magic spell cast on him that makes him smaller. Maybe a mischievous god or a powerful enemy uses a spell to shrink him for their own amusement or to gain an advantage in a battle. This would lead to some interesting situations where Annabeth has to protect him in a different way than usual.
One possible plotline could be Percy going on a desperate search for Annabeth. He might start by retracing her last known steps, asking all their mutual friends and allies if they've seen her. Another could be Percy having to face some old enemies alone in his search, as Annabeth was usually the one who strategized with him. And he could also discover some hidden secrets about Annabeth's past during the search that he never knew before.
One possible plotline could be Percy trying to escape the Hydra experiment facility while using his demigod powers. He might have to fight off Hydra agents and other dangerous creatures they've created through their experiments.
A possible plotline could be that Percy is somehow cursed to be a forgotten god. He has to figure out who cursed him and why. In his quest, he may find that there are other forgotten gods and goddesses who are also trying to break free from the same fate. He could team up with them and use his unique skills as Percy Jackson, even in his forgotten state, to fight against the forces that are keeping them in obscurity. This could involve battles with powerful magical entities, exploration of long - lost realms, and the discovery of new powers within himself that are related to his new 'forgotten god' status.
In this fanfiction, the imprinting might also be a source of internal conflict for Leah. She could struggle with her newfound feelings and loyalty towards Percy while also having her own personal goals and identity. Maybe she has to make a choice between following Percy on his adventures and fulfilling her own responsibilities, and this internal struggle could drive the plot forward.