A plot could revolve around Isles getting into some kind of trouble outside of work, like being wrongly accused of something in her personal life, and Rozzoli has to use his detective skills to clear her name while also dealing with his own feelings for her. For example, he might have to go against some powerful people who are determined to frame Isles.
Another plot could be that they go on a trip together for a case, but get stranded in a small town. While there, they start to discover some dark secrets about the town that are related to a series of disappearances. This would force them to work closely together in an unfamiliar environment and perhaps bring out some hidden feelings between them.
One idea could be a mystery where they have to solve a case that involves an old enemy from their past. Maybe this enemy has a personal vendetta against them and is setting up elaborate traps.
A new detective in their department could be a great character. This detective could be young and eager, but also a bit of a rival to Rozzoli. He might have different methods of solving cases and could create some tension in the team. At the same time, he could also develop a friendship with Isles, which might make Rozzoli a bit jealous.
Maybe a fanfiction where they have to solve a crime that hits a bit too close to home for Isles. Rizzoli has to be extra supportive, and in the process, they discover new things about each other's pasts that they hadn't known before. This could add more depth to their relationship.
One plot idea could be that Jane is kidnapped by a criminal she put away in the past who has escaped and is seeking revenge. Her partner Isles has to race against time to find the clues Jane left behind before it's too late. Another could be that a serial kidnapper targets Jane because of her detective skills, thinking she'll be a worthy challenge. Isles then uses her medical knowledge and understanding of Jane to figure out where she might be held.
You can start by looking on fan - fiction websites such as Archive of Our Own (AO3). It has a large collection of fan fictions, and you can search specifically for Rizzoli and Isles ones. Just type in the show's name in the search bar, and it will show you various stories.
One idea could be that a case in Boston (Rizzoli and Isles' territory) has connections to a military - related case that NCIS is investigating. For example, a murder victim in Boston turns out to be a former Navy officer, and both teams have to work together to figure out the motive and the killer. They might clash at first due to different investigation styles, but then gradually learn from each other.
You could have a plot where a character in a book - based fan fiction discovers that they are actually a character in a book within the story. They then try to change the course of the story. In a movie - based fan fiction, a side character could get the main character's powers accidentally and has to deal with the consequences while trying to keep it a secret from the other characters.
One interesting Rizzoli and Isles fan fiction could be one that focuses on their early days as partners. It might explore how they overcame initial differences and learned to trust each other. For example, a story where they have to solve a case that hits close to home for one of them, and through that experience, their bond deepens.
Well, you could have a survivor fan fiction where a contestant has a hidden skill, like being able to communicate with animals on the island. This could give them an edge in finding food and avoiding danger. Or perhaps a story where there's a traitor within the group, someone who is secretly working with the show's producers to create more drama. Also, a plot where the survivors find a map that leads to a hidden part of the island with a bountiful supply of food and shelter.
One idea could be that the Ghostbusters discover a new type of ghost that can possess technology. So they have to find a way to stop it from taking over all the electronics in the city. It would be a race against time as the city starts to descend into chaos with machines going haywire.
One idea could be a story where a minor character from the game gets a chance to become a hero. For example, a low - level soldier who discovers a hidden power within himself and uses it to save his comrades during a crucial battle.