Some 'castle crossover fanfiction' could cross it with a fantasy world, like 'Game of Thrones'. Picture Castle finding himself in the middle of the power struggles in Westeros. He would use his writing skills and his knowledge of human nature to navigate the dangerous political landscape there.
One popular 'castle crossover fanfiction' might be one that crosses 'Castle' with a detective show like 'Sherlock'. In such a story, Castle and Sherlock could team up to solve a complex mystery. The different deductive styles of Castle and Sherlock would create interesting interactions.
One popular 'castle oc fanfiction' story could be about an original character (OC) who is a detective in the Castle universe and teams up with Castle and Beckett to solve a mystery. There are also those that focus on the backstory of an OC, like how they got into the world of crime - solving in Castle's world.
Some fanfictions center around their cases. They might expand on a case from the show that seemed really interesting but was not fully developed. For instance, a story could be written from the perspective of Castle and Beckett when they were on a particularly dangerous undercover mission. These types of stories add more depth and detail to the events that happened in the show.
One popular 'castle beckett fanfiction' story could be about their adventures in an alternate universe where they solve crimes in a steampunk - style city. Another might focus on their relationship development during a long - undercover mission.
One popular story could be 'A New Beginning' where Beckett and Castle face a new mystery together that also deepens their relationship in a unique way. Another might be 'Unspoken Feelings' which delves into the unexpressed emotions between them.
One popular 'castle crossover fanfic' could be one that crosses 'Castle' with a detective story from another universe. For example, a crossover with Sherlock Holmes. The characters from 'Castle' might interact with Holmes and Watson, creating interesting scenarios where Castle's more light - hearted detective style clashes or complements the deductive reasoning of Holmes.
Crossovers between 'Sherlock' and 'Elementary' can be interesting too. Imagine Sherlock Holmes from the BBC's 'Sherlock' and Joan Watson from 'Elementary' working together on a case that spans both their versions of New York City. It would be a clash of different interpretations of the classic characters.
Well, a common trope is the 'fake relationship' one. In castle fanfiction, Castle and Beckett might pretend to be a couple for a case or some other reason, and then of course, real feelings start to develop. Also, the 'secret relationship' trope is popular. They keep their relationship a secret from their colleagues, adding an element of mystery and excitement. There's also the 'time - travel' trope where one or both of them travel through time and they have to navigate their relationship in different time frames.
One popular castle fanfic could be those that explore different relationships between the characters in a castle setting. For example, stories might focus on the friendship or romance between a knight and a princess in the castle. Another type could be about the secrets and mysteries within the castle walls, like hidden passages and forgotten treasures.
One idea could be that Brennan and Castle team up to solve a crime that has elements related to both their areas of expertise. Maybe it involves a historical skeleton discovery at a crime scene Castle is investigating.
One idea could be to have the characters from Firefly somehow land near the castle. Maybe they are in need of supplies and the castle inhabitants initially view them as a threat. Then, through a series of events, they start to work together, with the Firefly crew sharing their space - traveling knowledge and the castle people providing shelter and local resources.