One way to develop their relationship is through shared experiences outside of work. Maybe they both attend a community event related to a case they worked on. There, they see a different side of each other. Also, the OC could have a personal problem that Horatio helps with, like dealing with a difficult landlord. This would create a bond of gratitude and deepen their connection. Another aspect could be that they have different views on crime - solving methods, and through debating and finding common ground, their relationship evolves.
To develop their relationship, it could start with the OC being in awe of Horatio's reputation as a top CSI. As they interact more, Horatio discovers the OC has a unique way of thinking that challenges his own. They could have moments of conflict, but then resolve them in a way that strengthens their bond. For instance, in a case where the OC's unorthodox approach almost gets them in trouble, but Horatio defends them. This would show that Horatio values the OC, and from there, their relationship can progress further, perhaps into a mentorship or a close friendship.
The relationship can start with mutual suspicion. Horatio might be cautious of the OC's motives at first. Then, as they work on cases together, they begin to respect each other's skills. For example, if the OC is good at computer hacking and helps Horatio access crucial evidence. This mutual respect can grow into a friendship over time.
There are often fanfics that explore the backstory of how Horatio and the OC became like brothers. Maybe they started off not getting along, but through a series of events, like facing a common enemy or working through a personal crisis together, they grew closer. A fanfic could focus on that journey of their relationship evolving into a brotherly one.
One common theme is the integration of the OC into the CSI Miami team. Usually, the OC has to prove themselves and find their place among the established characters, like Horatio. Another theme is the solving of complex crimes. The OC often brings in a fresh perspective that helps Horatio and the team in their investigations.
One idea could be a story where Horatio and the OC meet through Jesse. Maybe the OC is a forensic expert new to Miami and Jesse introduces them to Horatio. This could lead to a series of investigations where they all work together and gradually form a deep friendship.
A common theme is the mentorship. Horatio often acts as a mentor to Jess in many fanfics. For example, in some stories, he teaches her how to handle the tough situations in the CSI Miami environment.
A third common theme is mystery. Just like in the CSI Miami show itself, the fanfics usually revolve around solving some sort of mystery or crime. The niece might be directly involved in the case, or she could be a side character who is affected by the events. There's also often a bit of drama, whether it's between the niece and other characters on the team, or related to the mystery at hand, like secrets being uncovered that impact the story's progression.
A possible plot is that the OC is a journalist who is covering a big story in Miami. They cross paths with Horatio and Jesse during their investigations. The OC starts to get too close to the truth of a dangerous case and Horatio and Jesse have to decide whether to trust the OC or keep them at bay. As the story unfolds, they all realize they need to work together to expose the real criminals.
One common theme is family. Writers often explore the relationship between Horatio and his daughter, showing how they support each other through difficult times in the CSI Miami world. For example, his daughter might be in danger because of his job, and the story could revolve around how he protects her.
The theme of family, beyond just blood relations, is also prevalent. They might not be related by blood, but in the fanfics, their bond is as strong as any family tie. They celebrate holidays together, support each other during personal losses, and are always there to celebrate each other's successes.
A plot could revolve around the OC being a former criminal who has turned their life around and now wants to help Horatio solve crimes. There could be a lot of tension as Horatio is initially skeptical but then realizes the OC's value. Maybe there's a case where the crime is related to the OC's past and they have to face their old demons while working with Horatio. Also, a plot where the OC is a forensic expert from another country and brings a different perspective to Horatio's cases in Miami.
One great CSI Miami Horatio OC fanfic is 'Horatio's New Ally'. It has an interesting plot where the original character is a forensic expert from another country who teams up with Horatio. The character development is really well - done, and it shows how they overcome differences in their approaches to solving crimes.