One creative idea is a time - travel crossover. For example, the characters of Brooklyn Nine - Nine traveling back in time to a different era, like the 1920s, and having to solve crimes while dealing with the cultural differences of that time. It's a really cool concept.
Another creative concept is a crossover with a superhero universe. Picture the detectives of the Nine - Nine suddenly having superpowers or having to deal with superheroes in their city. It completely changes the dynamic of the show and allows for a lot of action - packed and humorous scenarios.
A crossover with a fantasy world is also very creative. The Nine - Nine characters find themselves in a magical realm where they have to use their detective skills in a completely different context. They might have to solve the mystery of a missing magical artifact, for example, and it's fascinating to see how they adapt to this new world.
One idea could be a crossover with 'The Office'. Picture Holt trying to implement his strict rules in the Dunder Mifflin office and the chaos that would ensue. Jim could play pranks on the Brooklyn Nine - Nine characters, while Terry would try to keep everyone in line. Another idea is a crossover with 'Parks and Recreation'. Leslie Knope and Jake Peralta could team up to solve a mystery that involves both Pawnee and the 99th precinct. They would have very different approaches, but it would be fun to see them work together. A third idea could be a crossover with 'Stranger Things'. The Brooklyn Nine - Nine gang could find themselves in Hawkins dealing with the Upside Down. Scully and Hitchcock would probably be the first ones to run away from any demogorgons!
One interesting plot idea is a role - reversal. The Young Justice characters could find themselves in the Brooklyn Nine - Nine world, having to adapt to normal, non - superhero life. They'd have to deal with things like paperwork and office politics, which would be a huge change for them.
If it's a crossover with 'Game of Thrones', Tyrion Lannister would be a very interesting character to include. His wit and intelligence would play well against the characters in Brooklyn Nine - Nine. He could outsmart some of the criminals while also getting into comical exchanges with Jake and the gang. Another great addition would be Arya Stark. She could show off her combat skills and stealth, and it would be interesting to see how she interacts with Rosa, who also has a tough - as - nails attitude. Also, Jon Snow could be included. His sense of honor and leadership could have an impact on how the precinct operates, especially when dealing with difficult cases.
There's also a Brooklyn Nine - Nine and 'Parks and Recreation' crossover fanfiction. In it, the Pawnee gang meets the Nine - Nine crew. Amy Santiago and Leslie Knope would probably bond over their love for organization and efficiency. It's a fun read as they all get into various misadventures together.
Amy Santiago is also very popular. Given her competitive and organized nature, there are many fanfictions that explore her relationship with Jake further, like their married life or how they balance their careers and family. Also, her friendships with the other female characters in the show can be a focus in some fanfictions.
Character backstories are often explored in brooklyn nine nine fanfiction. Fans like to dig deeper into where the characters came from, what made them who they are. For instance, Holt's journey to becoming the captain, including his experiences in his early career in the police force, can be a rich area for fanfiction writers to explore.
Many Brooklyn Nine - Nine OC fanfictions have the theme of contribution. The OC tries to contribute to the precinct in their own unique way, whether it's solving a difficult case that the others couldn't or bringing in a new skill or perspective. This theme ties in with the idea of acceptance, as the other characters gradually accept the OC based on their contributions.
One plot idea could be Amy trying to balance her pregnancy with her detective work. Maybe she's determined to solve a big case before going on maternity leave and has to deal with the overprotectiveness of her colleagues, especially Jake. Another could be the hilarious baby shower preparations at the precinct, with everyone having different and comical ideas about how to celebrate.
A really interesting fanfiction might be set in an alternate universe where the characters have different jobs but still maintain their unique personalities. Maybe Holt becomes a college professor, and the others are his students in a way, and there are comical and heartwarming interactions.
One common theme is the culture clash. The Avengers with their superpowers and global - saving missions meet the wacky, police - station - based world of Brooklyn Nine - Nine. It makes for some really funny situations.