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.
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.
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.
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 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.
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.
Maybe Prince William stumbles upon Harry Potter during one of his wizarding battles. Using his royal influence or some hidden magical ability (in this fictional scenario), he manages to save Harry from a dangerous situation, like a Death Eater attack.
In this fanfiction, the Delacours might rescue Harry by using their knowledge of the wizarding world outside of Hogwarts. They could have some secret passages or allies that Harry wasn't aware of. For instance, they could lead Harry through a hidden route in the French wizarding community that the enemies don't know about.
In fanfiction, it could be that the NCIS has some sort of magical knowledge or artifacts. Maybe they've been dealing with cases that are on the fringes of the wizarding world without realizing it. When they discover that Harry Potter is in danger, they use this knowledge or these artifacts to save him. For instance, they could have an ancient amulet that can counter dark magic spells aimed at Harry.