Another plotline might involve Tom believing that Harry has some hidden power that he can extract or use for his own dark purposes. So, he kidnaps Harry to figure out how to access that power. This could lead to a series of attempts by Tom to break Harry's will and get him to reveal the secret. For example, he might put Harry in a magically sealed room and use various spells to try and force the information out of him. Harry, on the other hand, could be trying to resist and find a way to escape or signal for help.
Perhaps Tom kidnaps Harry because he sees Harry as a symbol of the resistance against him. By capturing Harry, he hopes to demoralize the forces that oppose him. In this scenario, Harry's friends would then have to mount a rescue mission. They would need to figure out where Tom is hiding Harry, which could involve a lot of detective work, like following Tom's known associates or looking for any magical trails he might have left behind.
Perhaps in the fanfiction, Harry adopts Tom Riddle when he's still a young boy at the orphanage. Harry then uses his own experiences of growing up without parents to bond with Tom. He teaches Tom about magic in a different way than Dumbledore did, focusing on the positive aspects of magic for good. This could lead to Tom not becoming the evil Voldemort we know.
The themes could also include redemption. After kidnapping Marco, Tom might realize the error of his ways and try to make amends. And there could be a theme of friendship. Even though Tom has kidnapped Marco, the story could explore if their friendship can be salvaged.
One possible plotline could be that Cato kidnaps Katniss as a strategic move in the Hunger Games. Maybe he thinks he can use her to draw out other tributes or get an advantage over the Careers. Another could be that Cato has some sort of personal vendetta against Katniss that leads him to kidnap her outside of the normal rules of the Games.
One possible plotline could be Bella's friends and the Cullens coming together to rescue her. They might plan a stealthy infiltration of Aro's lair, using their unique abilities. For example, Alice could use her visions to anticipate Aro's moves and find the safest way in.
Perhaps the rogue is hired by an evil force to kidnap Lucy. She could be the daughter of an important figure or a person with unique abilities that the evil force wants to use against the good side. As the story progresses, Lucy could try to escape or even try to turn the rogue to her side by appealing to his better nature.
One possible plotline could be Buffy's friends rallying together to rescue her. They might use their unique skills, like Willow's magic, to track down Angelus and his lair.
Well, it could be that Lucy has a misunderstanding. Maybe she overhears something that makes her think Natsu is planning to leave the guild without saying goodbye. So, in a fit of panic and anger, she kidnaps him to get an explanation. Then, as the story progresses, they have a heart - to - heart conversation where the misunderstanding is cleared up. It could also be a situation where Lucy is competing with someone else for Natsu's attention, and she thinks that by kidnapping him, she can have him all to herself for a while and figure out how to make him like her more.
One possible plotline could be Harry initially resists the idea of being Tom Riddle's submissive mate but gradually finds himself drawn to Riddle's power and charisma in a complex way. Maybe they are forced to work together against a common enemy and during that time, their relationship evolves.
One possible plotline could be a magical accident that leads to the pregnancy. Maybe a spell gone wrong during a battle or an experiment.
Another plotline might involve Karasu having a personal vendetta against Keiko or someone close to her. He kidnaps her to exact revenge in a more elaborate and drawn - out way. This could lead to a series of events where Keiko tries to outwit Karasu and escape while also uncovering the true reasons behind his actions. And during this process, there could be unexpected alliances and betrayals.