Perhaps a fanfic where Hetty's sister is an old acquaintance of one of the NCIS LA agents. She shows up with a mystery from their past that they all have to solve together. This could lead to flashbacks and revelations about the agent's early days, and how Hetty's sister was a part of it all.
The plot could be that Hetty's sister, an original character (oc), comes to work with the NCIS LA team temporarily. She has a unique skill set, like being an expert in a particular type of forensics that the team lacks. However, her presence also stirs up some old rivalries within the agency because of her connection to Hetty.
Well, it might be that the OC has a personal connection to an ongoing case. Hetty, being the shrewd character she is, hires the OC to use that connection to the team's advantage. Perhaps the OC has a past with a criminal organization that the NCIS LA team is currently investigating, and their inside knowledge could be crucial.
One great NCIS LA Hetty Daughter OC fanfic is 'The Hidden Legacy'. It delves deep into the character of Hetty's daughter as an original character. The story is filled with intrigue as she gets involved in the NCIS LA operations in a unique way. It has great character development and a plot that keeps you hooked from start to finish.
The main thing is the exploration of new relationships. Since the daughter is an OC, the writer can create unique dynamics between her and the existing characters. For example, her relationship with Hetty can be explored in ways not shown in the original show. It could be a strained relationship or a very close - knit one depending on the writer's take.
The OC could also impact the team's morale. If they are highly motivated and positive, it could boost the overall mood of the team. On the other hand, if they struggle in their new role, it could put some pressure on the team to help them out. But overall, their presence would likely force the team to reevaluate their own roles and relationships as they adapt to having this new member around.
One possible plotline could be that O'Neill's sister gets involved in a case that Granger's daughter is also working on. Maybe they start off on the wrong foot but then gradually learn to work together and in the process, O'Neill has to play mediator between them.
A fanfic that stands out is 'OC's Impact on Callen'. This one focuses on how the OC changes Callen's perspective and his way of handling cases. The OC is portrayed as a strong - willed and intelligent character, and the way they interact with Callen is both engaging and believable. It also has some great action scenes that are typical of the NCIS LA style.
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.
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.
In fanfic, she could also be a bit of a rebel. Tired of living in her father's shadow, she might try to carve out her own identity in the NCIS world. This could lead to some interesting conflicts, both with her father and with the other characters in the story.