Well, in some versions of 'Stiles is kidnapped fanfiction', the kidnappers could be from an enemy faction within the supernatural community. Stiles might be used as a bargaining chip. His friends would then have to decide whether to give in to the kidnappers' demands or find a way to rescue him without compromising. It could also be that Stiles discovers a hidden power or ability while kidnapped, which he then uses to escape. For example, he could have a latent psychic ability that gets triggered by the stress of the situation.
One possible plotline could be that Stiles' friends immediately start a search. They might follow clues like strange footprints or a mysterious note left behind. Another could be that Stiles manages to outwit his kidnappers in some way while being held captive, perhaps by tricking them into revealing their weaknesses. Maybe the kidnappers are after something Stiles knows, like a secret about the supernatural world in the fanfiction's setting.
One possible plot could be that Theo kidnaps Stiles to use him as a bargaining chip with the pack. Maybe Theo wants something from Scott, like the alpha power or a powerful artifact that the pack has in their possession, and he thinks Stiles is the key to getting it.
One possible plotline could be that Yami is kidnapped by a rival group who wants to use his special powers for their own evil deeds. His friends then embark on a dangerous mission to rescue him. Another could be that Yami is kidnapped as part of a ransom plot against someone he is close to, and they have to figure out how to meet the kidnappers' demands without sacrificing too much.
Well, it could start with Mycroft being lured into a trap and kidnapped. The kidnappers might be from a different dimension or have some sort of supernatural power. As the fanfiction progresses, Mycroft could use his wits to outsmart the kidnappers even while in captivity. There could be a lot of mind games and tense moments as he tries to escape or signal for help.
Perhaps in this 'imprijt kidnapped fanfiction', the kidnapped person is a key figure in a grander scheme. Imprijt kidnaps them to use as a bargaining chip against their friends or allies. The friends then embark on a rescue mission filled with various challenges and unexpected twists.
One possible plotline could be that Naruko is kidnapped by a powerful enemy who wants to use her as a bargaining chip against her friends or family. Another could be that she is kidnapped by a mysterious organization for some sort of experiment. Maybe she's kidnapped by someone who has a personal vendetta against her and plans to make her suffer.
One possible plotline could be that Keith is kidnapped by an enemy force. His friends then embark on a dangerous rescue mission, facing various challenges along the way. Maybe they have to infiltrate a heavily guarded enemy base to find and free him.
One possible plotline could be that a deranged fan kidnaps the Beatles in an attempt to force them to play a private concert just for them. Another could be that a rival music group arranges the kidnapping to try and stop the Beatles' rise to stardom.
One possible plotline could be that Twilight Sparkle is kidnapped by a powerful dark magic user who wants to steal her knowledge of magic. Her friends then embark on a quest to rescue her, facing various challenges along the way. Another could be that she is kidnapped by an unknown force from another dimension for some sort of experiment. Her friends have to figure out how to cross dimensions to save her. A third plotline might be that a group of villains kidnap Twilight Sparkle to use her as a bargaining chip against Equestria, and her friends must find a way to outwit the villains and get her back safely.
One possible plotline could be that Natasha is kidnapped by a rival organization seeking to extract information from her about S.H.I.E.L.D. secrets. They might try various forms of interrogation, but Natasha, being the tough spy she is, manages to hold out and start planning her escape. Another could be that she's kidnapped by someone with a personal vendetta against her past as a Black Widow, perhaps a family member of someone she killed during her assassin days. They want to make her pay for her past actions.
One possible plotline could be that Lan is kidnapped by a group of rogue NetNavis who want to use his unique connection to MegaMan for their own evil purposes. They might try to force Lan to give up access codes or secrets about MegaMan's abilities.