The plot could involve a magical artifact that Harry Potter is trying to protect. This artifact has somehow made its way into the world of NCIS. Dark wizards want to get their hands on it and will stop at nothing. Harry is in over his head as he tries to deal with both the Muggle law enforcement and the powerful magic of his enemies. NCIS agents, with their own code of honor and sense of justice, step in to rescue Harry. They start to learn about the magical world as they help him, and together they come up with a plan to keep the artifact safe and get Harry back to Hogwarts.
Maybe the Fem Harry Potter is being hunted by Voldemort's followers in a new and unexpected way. The NCIS agents rescue her, but then find out that there are spells on her that are affecting the Muggle world around them. They need to find a way to break the spells while also keeping her safe from the Death Eaters. This could lead to some interesting interactions between the two very different worlds.
The NCIS agents, being highly trained professionals, would approach Harry in a very matter - of - fact way. They would be a bit skeptical about his claims of magic at first. Harry, on the other hand, would be amazed by the Muggle technology that NCIS uses. There could be some humorous moments when Harry accidentally does something magical, like making a pen levitate, and the agents are completely stunned. As they work together to escape the bad guys, they would gradually develop respect for each other's abilities.
In this fanfiction, perhaps Harry Potter is brought into NCIS because there are rumors of a wizard - made weapon being used in crimes. He would have to navigate the non - magical world of law enforcement while also keeping his own magical identity a secret. His owl, Hedwig, could be used to send messages in a discreet way that NCIS could benefit from. He might also introduce some of his wizard friends, like Hermione, to help with research using magic - enhanced techniques.
The plot could involve the goblins rescuing Harry when he is being wrongly accused of a crime in the wizarding world. They could believe in his innocence and use their unique skills and knowledge of magic to keep him safe. Maybe they help him prove his innocence later on. They might also have their own motives for helping Harry, like they see him as a key to some sort of change in the relationship between wizards and goblins.
One possible plot could be that Harry is wrongly accused of a crime in the wizarding world, perhaps something related to dark magic. The police, who might be a new magical law enforcement unit, rescue him from an angry mob. They then help him clear his name by finding the real culprit, who could be a Death Eater in disguise trying to frame Harry to cause chaos in the post - Voldemort era.
There could be some comical interactions. For example, the NCIS agents might try to use their standard interrogation techniques on Fem Harry Potter, which would be completely ineffective since she's used to a different set of rules in the wizarding world. Meanwhile, Harry might accidentally use magic in front of them in a moment of panic, causing chaos. As they get to know each other better, the NCIS agents could start to learn some basic magic defense spells from Harry, while Harry learns about Muggle self - defense and investigation methods from the agents.
One possible plot could be that Harry Potter uses his magical skills to solve a case that NCIS is stumped on. For example, he could use the spell 'Revelio' to find hidden evidence that normal forensic techniques couldn't detect. His knowledge of the wizarding world might also lead him to suspect that a suspect is using some form of dark magic or enchanted object in their crimes.
One possibility could be that Voldemort rescues Harry Potter for some self - serving reason. Maybe he realizes that Harry holds the key to a greater power that he wants to obtain. So, instead of killing Harry, he saves him from another threat, like a powerful dark wizard who is trying to overthrow Voldemort and sees Harry as a useful tool as well. In this fanfiction, Harry would be in a very strange situation, having to trust Voldemort at least temporarily.
In this kind of fanfiction, perhaps Harry is rescued by the Order of the Phoenix earlier than in the original story. They might have realized the Dursleys' mistreatment sooner. Then Harry could start his magical training earlier, away from the hostile environment of the Dursleys' home. He may also form closer bonds with other members of the Order, like Sirius, who could play a more active role in his upbringing.
One idea could be that the NCIS team is called in to investigate some strange magical occurrences in the wizarding world. Maybe they think it's some new form of high - tech weaponry at first but then realize it's magic. Another could be that Harry Potter and some of his friends end up in the NCIS world and have to work with the team to solve a mystery that involves both magic and muggle technology. For example, a dark wizard is using muggle technology to enhance his magic and they need to stop him.