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.
A possible plot could involve a missing person who has a connection to both Hawaii and LA's military. Hawaii Five - 0 starts the search in Hawaii and discovers that the person was last seen with some individuals who are under NCIS LA's surveillance. This leads to the two teams collaborating. They face many obstacles along the way, like interference from some powerful and shadowy organizations who don't want the person to be found.
One idea could be that the BAU is called in to help the NCIS LA team when a series of murders seem to be related to a military - civilian connection. The agents from both teams could clash at first due to different working styles, but then gradually learn from each other and solve the case together.
One great 'NCIS LA and NCIS Crossover Fanfiction' is 'The Joint Operation'. It combines the unique characters from both shows really well. The plot usually involves a case that requires the expertise of both teams. It shows how the agents from NCIS and NCIS LA interact, like how Gibbs' no - nonsense approach clashes and also gels with Hetty's more mysterious style of leadership.
One common theme is the cooperation between the two teams. Since they come from different but related agencies, the fanfictions often focus on how they learn to work together. For example, they might have to overcome differences in their investigative techniques.
One reason is the expansion of the universe. By crossing over, fanfiction writers can explore new relationships between characters. They can put characters in situations that test their limits and abilities. Moreover, the fans are already attached to the characters from both shows. So when they are combined, it's like a dream come true. It gives a chance to see how the LA - based agents would handle a case that's more in the realm of the original NCIS and vice versa.
One popular NCIS and NCIS LA crossover fanfiction is 'Combined Forces'. It brings together the characters from both shows in an exciting case that spans across the two teams' jurisdictions. The story does a great job of capturing the personalities of each character, like Gibbs' no - nonsense attitude and Hetty's mysterious allure.
A scenario could be a missing person case that spans both areas. The NCIS LA team starts the investigation on the mainland when they realize the person might have headed to Hawaii. Then they call in the Hawaii 5 - 0 team for help. As they search, they discover that the missing person is involved in some sort of international conspiracy that both teams have to unravel.
In a crossover fanfiction, you could focus on the relationships between the characters. Perhaps there could be a bit of friendly rivalry at first between the two teams. But as they work together, they start to respect each other more. For instance, some of the more serious - minded characters from NCIS LA might initially clash with the more easy - going ones from Hawaii 5 - 0. However, by the end of the story, they become good friends and allies, having learned from each other's ways of doing things.
You can try fanfiction websites like Archive of Our Own (AO3). It has a large collection of fan - created works, including many NCIS and NCIS LA crossovers. Just use the search function and type in relevant keywords to find what you're looking for.
A plot could revolve around a character from one show being framed for a crime, and the other team has to step in to prove their innocence. For example, a member of the Five - 0 team is wrongly accused of stealing military secrets, and the NCIS Hawaii team uses their resources to dig deeper and find the real culprit. This could lead to some great character interactions as they learn to work together.