A plot twist might be that Shawn was actually expecting to be kidnapped. He could have been working undercover on a case and let the kidnapper take him on purpose to get closer to the real bad guys. It could also turn out that the kidnapper is a deranged fan of Shawn's detective work. They kidnapped him not to harm him but to force him to solve a mystery that only they believe in. And there's the chance that the whole kidnapping is an elaborate illusion created by Shawn himself as part of a bigger plan to expose a criminal organization that has been one step ahead of the police for a long time.
One possible plot twist could be that the person who shot Shawn was someone he knew and trusted, like a former client who had a hidden agenda. Another twist could be that the shooting was a case of mistaken identity, and Shawn was actually targeted because of someone else's actions.
One common plot twist could be that the injury Shawn sustains is part of a larger conspiracy. Maybe someone set him up to get hurt in order to keep him from uncovering a big secret. Another twist might be that his injury leads to him having some sort of special ability or insight. For example, while recovering, he starts to notice details he never did before, which helps him solve a case in a completely unexpected way. Also, it could be that the person who is supposed to be helping him with his injury is actually the one who wants to harm him further, adding a lot of suspense to the fanfiction.
The kidnapper could be an obsessed fan of Shawn's. They might have started off as a big admirer of his detective skills but then their admiration turned into an unhealthy obsession. Maybe they want Shawn all to themselves and think that kidnapping him is the way to achieve that. Or it could be someone who has a grudge against Shawn's father. Since Shawn is so close to his father, they figure that by kidnapping Shawn, they can get back at his dad. It could also be a member of a secret organization that Shawn has unknowingly been interfering with in his investigations.
One idea could be that Shawn is kidnapped by a criminal who he once wrongfully accused. This criminal wants to make Shawn pay for ruining his life. Another plot could involve Shawn being kidnapped as part of a bigger conspiracy related to a case he's currently working on. Maybe the kidnapper is trying to stop him from uncovering the truth. Or perhaps Shawn is kidnapped by a deranged fan who has an obsession with him and wants to keep him all to themselves.
A great plot twist would be if Raven is kidnapped and taken to a place where she meets her long - lost family members, but they're the ones who kidnapped her because they need her help to fight against a common enemy, and they knew this was the only way to get her attention. Another plot twist could be that the kidnapper has a split personality, and one side is good and wants to free Raven, while the other side is evil and wants to keep her captive. And the last plot twist might be that Raven is kidnapped into a parallel universe where everything is different, and she has to find a way back while also dealing with the kidnapper in this strange new world.
The story could end with Shawn using his wits to escape. He might trick his kidnapper into believing he's on their side and then make a run for it when they least expect it.
Sometimes, the plot twist is that Stiles is actually in on the kidnapping in a way. Maybe he's trying to protect his friends from a greater danger by faking his own kidnapping. So all the while his friends are searching for him, he's actually on a secret mission of his own, which is revealed later in the story and makes for a really interesting read.
One common plot twist could be that the kidnapper is someone Allen thought was a friend all along. It adds a sense of betrayal and shock to the story.
In some fanfictions, a plot twist could be that Haruhi's kidnapping is part of a virtual reality game that she unknowingly entered. The 'kidnappers' are just players in the game who are trying to win by capturing her. Another common plot twist is that the kidnapper has a change of heart halfway through. They start to see Haruhi's good qualities and instead of harming her, they end up helping her. And sometimes, it could be that the kidnapping is a test set by a mysterious organization to see if Haruhi is worthy of some special task or knowledge.
When Shawn gets shot in the fanfiction, it could be a turning point for his character. He might become more serious and less of the carefree psychic he was before. His relationship with his father could also change. His father, who has always been a bit tough on him, might realize how much he truly cares about Shawn. Meanwhile, Juliet would be by his side, torn between her detective duties and her feelings for Shawn. She would be determined to find the person responsible for shooting him, and this could lead to some intense and emotional scenes between them.