In a Nightwing and NCIS crossover fanfiction, the plot might revolve around a stolen military weapon that has been modified by a Gotham - based villain. The NCIS team is called in to find the weapon, and they cross paths with Nightwing who is also after the same villain for other reasons. Nightwing has his own network in Gotham that can provide information about the villain's whereabouts, while NCIS has access to military databases and resources. Together, they follow the trail of the weapon, facing off against the villain's henchmen and uncovering a conspiracy that goes deeper than expected.
One possible plot could be that Nightwing is somehow involved in a case that crosses over into the NCIS jurisdiction. Maybe there's a criminal organization dealing with both high - tech gadgets (Nightwing's area of expertise) and military - related crimes (NCIS). The NCIS team initially suspects Nightwing but then realizes he's an ally and they team up to take down the bad guys.
Well, perhaps in this fanfiction, there's a multiverse rift that pulls Nightwing into the Avengers' world. The Avengers initially mistake him for an enemy, but after some misunderstandings are cleared up, they realize his skills. Together, they face a new threat created by a combination of Hydra and some of Nightwing's rogues gallery who have also crossed over. Nightwing could teach the Avengers some stealth tactics while they show him how to handle more powerful cosmic threats.
At the start, the NCIS agents would likely view Nightwing as an unknown vigilante. But as they get to know him, they'd see his value. For example, Tony from NCIS might crack some jokes at Nightwing's expense at first, but then be impressed by his detective skills. Abby would be fascinated by Nightwing's gadgets. And as for Nightwing, he'd adapt to the NCIS agents' more official and structured way of doing things. He might also share some of his knowledge about the criminal underworld in Gotham with them, which could be very useful in their investigation.
One possible plot could be that they team up to stop a powerful villain who has the ability to travel between their two cities. Maybe this villain is stealing tech from Gotham and super - powers from New York. They start off not trusting each other as they have different methods. Nightwing is more stealthy and trained in combat, while Spider - Man is more quippy and uses his webs in a very acrobatic way. But as they face challenges together, they learn to work as a team and combine their skills to take down the bad guy.
One possibility could be that Alex Rider is on an undercover mission that somehow intersects with an NCIS case. Maybe he's tracking down a group involved in international espionage and they turn out to be linked to a crime on U.S. soil that NCIS is also investigating. For example, a terrorist organization that is smuggling weapons and using the sea routes which is NCIS' area of expertise. Alex could bring his unique skills in combat and infiltration, while the NCIS team offers their forensic and military investigation knowledge.
The plot could involve a powerful magical artifact that has military applications. The NCIS comes across this artifact during an investigation but doesn't understand its true nature. Percy Jackson and his friends, who are on a quest to retrieve the artifact for the demigod world, cross paths with the NCIS. There is a lot of miscommunication at first as the two groups have different goals and ways of operating. But as they realize that they are both facing a common threat from a group of rogue demigods and power - hungry military personnel, they join forces. Percy uses his knowledge of the demigod world and his powers to help the NCIS agents navigate the magical aspects while the agents use their resources and combat training to take on the human threats.
One possible plot could be that Tony, from NCIS, is on a case that somehow intersects with Davis and Okoye's world. Maybe it involves some sort of international conspiracy. Tony's investigative skills could be put to the test as he teams up with Davis and Okoye, each bringing their own unique abilities to the table.
Maybe the NCIS team stumbles upon a strange artifact that has the power to open portals to different dimensions. Unknowingly, they activate it and end up in the world of Sailor Moon. There, they meet Sailor Moon and her friends who are in the middle of a battle against the forces of evil. The NCIS agents, with their knowledge of forensics and combat skills, offer their help. In return, the Sailor Scouts teach them about the magic and powers in their world. Together, they form an unlikely alliance to defeat the common enemy.
One plot idea could be a joint case where the NCIS team and the NCIS LA team have to work together to solve a crime that spans across different locations. Maybe a terrorist threat that has connections in both Washington D.C. (where NCIS is based) and Los Angeles.
Another plot point is the combination of powers and skills. Naruto has his powerful jutsus, and the NCIS agents have their forensic and investigative skills. When they team up, they can use these in unique ways. For instance, Naruto could use his shadow clone jutsu to search a large area quickly while the agents analyze the evidence the clones find. This synergy between two very different sets of abilities makes for an exciting story.
Well, in a Stargate SG1 and NCIS crossover fanfiction, there could be a situation where an alien artifact is found at a crime scene that NCIS is investigating. The SG1 team is then called in to figure out what it is. Daniel Jackson could start rambling about the historical and alien significance of the artifact, while Abby from NCIS is trying to analyze it from a forensic perspective. It would be a great mix of science - fiction and crime - solving elements.