One idea could be that Sam is kidnapped by a group of rogue hunters who think he's gone too far in his use of demon powers. They lock him in an abandoned bunker and try to 'exorcise' the 'demon' out of him, not realizing he's in control. His brother Dean has to race against time to find him, following a series of cryptic clues left by the kidnappers.
Perhaps Sam gets hurt while trying to protect a civilian. He jumps in front of a werewolf's attack meant for someone else. This would show his selfless nature. The local hunters in the area might not trust Sam and Dean at first, but seeing Sam's sacrifice could change their minds, adding an interesting dynamic to the story.
Well, Dean would probably go into full - on search - and - rescue mode. He'd start by reaching out to all their contacts in the hunter community. Maybe he'd call Bobby in spirit form if he could, asking for any leads or advice. He'd also check Sam's last known locations and look for any signs of a struggle.
In fanfiction, if Sam was kidnapped, it could lead to a very intense story. Dean would surely go on a rampage to find him. Maybe Sam was kidnapped by a powerful demon who wants to use him for some dark ritual. It could also be a new, unknown enemy who has a vendetta against the Winchesters.
If Sam is kidnapped in Supernatural fanfiction, it could be a personal vendetta. There might be a hunter who has a grudge against the Winchesters and decides to target Sam. This hunter could have a different view on how to deal with the supernatural and thinks the Winchesters are too lenient. So, they kidnap Sam to make a point or to try and force Dean to change his ways. It would create a lot of tension and conflict within the Supernatural community in the fanfiction.
Well, it depends on the type of fanfiction. In darker fanfictions, Sam getting shot could be the start of a downward spiral for the Winchester brothers. Dean could become overly consumed with revenge if it was a hunter or a monster that shot Sam. On the other hand, in more positive fanfictions, Sam getting shot could lead to a moment of self - discovery. He might realize how much he has to live for and how many people rely on him. Maybe it makes him reevaluate his relationships, like his bond with Dean or his friends in the hunting community.
Often, the theme of family is central. Dean's reaction to Sam's psychic boost can vary from being supportive to being worried about how it will change their dynamic. Also, there's the theme of the unknown. The source of Sam's psychic boost might be a mystery, and exploring that mystery is part of the story. There can also be a theme of sacrifice, like Sam having to sacrifice normalcy to use this power for good.
Well, I'm not sure if it's still up, but there was a fanfic called 'Sam's Psychic Surge'. It was a bit of a darker take on Sam getting a psychic boost. The power came with a price, and Sam had to make some tough choices. It was really well - written in terms of exploring the moral implications of having such a powerful ability.
Perhaps Sam gets hurt while trying to protect a civilian in Flashpoint. The civilian feels guilty and tries to help in his recovery. This could lead to an interesting bond between them. Meanwhile, Sam's team is investigating who was behind the attack on the civilian that led to Sam's injury, and they uncover a conspiracy within the Flashpoint society.
One common theme is the struggle for survival. Sam has to find ways to endure the situation he's in while kidnapped. For example, in many stories, he might have to deal with lack of food or water.
I'm not sure specifically if there is a publicly available 'Totally Spies' fanfiction with Sam kidnapped. However, given the nature of fanfiction, it's very likely. Fanfiction writers often take beloved characters and put them in challenging situations. Sam is a popular character, and a kidnapping plot would be an exciting way to develop a story within the 'Totally Spies' universe.