For a 'a marriage of true minds fanfiction', you might consider setting it in a different time period or location. This would add a new layer of complexity to their relationship. For example, if they were in a historical setting, they would have to deal with the social norms and expectations of that era, which could either strengthen or strain their marriage of true minds.
Well, you could write a fanfiction where the BAU team gets trapped in a virtual reality world created by a tech - savvy unsub. They have to solve puzzles and cases within this virtual world in order to escape. Or perhaps a story where a new agent joins the team who has a psychic ability that they keep hidden at first. But as the cases progress, this ability starts to surface and help the team in unexpected ways.
One idea could be a crossover with The Hunger Games. The characters from Darkest Minds could be thrust into the arena, and their special abilities would give a new twist to the survival challenges. For example, Ruby's power to control minds could be used to manipulate other tributes or even the Capitol's forces.
One idea could be to have the Criminal Minds team investigate a series of strange disappearances in the wizarding world. They could use their profiling skills to figure out if it's a human or a magical creature behind it. Another could be to have a character from Harry Potter, like Hermione, collaborate with the Criminal Minds team. She could bring her knowledge of magic and spells while learning about modern profiling techniques from them.
Maybe in the fanfiction, a member of the CSI team has a personal connection to a case that the Criminal Minds team is investigating. This could lead to some intense emotional moments and also some friction between the two teams as they try to balance the need for objectivity with the personal investment. The story could explore how they overcome these challenges and solve the mystery behind the crimes.
One idea could be that the BAU team has to deal with a serial killer who is using ancient psychological torture methods. They have to quickly understand the killer's motives which are deeply rooted in some long - forgotten cultural practices.
One idea could be a vampire using their powers to manipulate crime scenes in ways that baffle the Criminal Minds team. For example, they could use their super speed to move evidence or their mind - control abilities on witnesses. Another plot could involve a vampire who is a serial killer, preying on victims in a pattern that the team has to figure out. Maybe the vampire has a moral code that only certain types of people are their targets, and the team has to understand this code to catch them.
One idea could be that the Scooby Gang from Buffy teams up with the BAU from Criminal Minds to solve a series of murders that seem to have a supernatural and a psychological aspect. Maybe the murders are being committed by a demon that is using human psychological weaknesses to target its victims.
A plot could involve Garcia's pregnancy being part of a dangerous case. The unsub could target her because of her pregnancy, seeing it as a way to get to the BAU. This would put her and her unborn child in great danger, and the team would have to go all out to protect her. Meanwhile, Garcia could also be dealing with her own fears and insecurities about becoming a mother in such a dangerous world.
One interesting plot idea could be a serial killer who targets both the FBI agents from Criminal Minds and the SWAT team members. The two teams have to combine their skills, with the Criminal Minds team analyzing the killer's psyche and the SWAT team providing on - ground protection and tactical support. For example, the killer might be leaving cryptic messages that only the profilers can decipher, while the SWAT team has to deal with the physical threats the killer poses during their investigations.
One idea could be that the Scorpion team is called in to help the Criminal Minds team with a case involving a highly intelligent criminal who is using complex technology to carry out their crimes. For example, the Scorpion team could use their skills to decrypt the criminal's encrypted messages that the Criminal Minds team couldn't crack on their own.