Perhaps they go on a road trip together to learn more about their family history. Along the way, they meet various people who knew their parents or have some connection to their family. This could lead to comical situations as Tony is more of a ladies' man and Reid is more socially awkward. And of course, they might also uncover some dark secrets about their family during this journey.
A plot could involve them dealing with family drama. Since they have such different personalities, they might clash when it comes to handling family issues. Tony might be more impulsive and Reid more analytical. They could also have to protect each other from a threat that targets their family. Maybe a criminal from one of their past cases holds a grudge against their family and they have to use their combined skills to stop the threat.
One plot idea could be that they discover they are brothers through a mysterious family secret. Maybe there's a hidden inheritance or a long - lost relative that leads them to this realization. Another could be that they have to work together to solve a crime that has a personal connection to their new - found brotherhood, with their different skills complementing each other. For example, Tony's street smarts and Reid's academic knowledge.
One interesting plot idea could be that Tony and Spencer are assigned a particularly difficult case. They have different approaches at first, with Tony relying on his street smarts and Spencer on his vast knowledge. As they work together, they start to understand and respect each other's methods more, and in the end, they solve the case in a way that combines both of their strengths.
One common theme is the clash and then the melding of their personalities. Dinozzo is often portrayed as the more practical and action - oriented one, while Reid is the brainy and sometimes naïve one. Their interactions based on these differences are a big part of many fanfictions.
As they face challenges together, their bond would strengthen. For instance, if they are in a dangerous situation, they would rely on each other. Tony might protect Reid in a physical confrontation, while Reid would use his knowledge to get them out of a tight spot intellectually. Over time, they would become more like a real family, sharing inside jokes and having each other's backs no matter what.
One great piece of Tony Dinozzo and Spencer Reid fanfiction is 'The Unlikely Bond'. It delves into their relationship as they work together on a complex case. The story really captures their different personalities well, with Dinozzo's more laid - back and street - smart nature contrasting Reid's intellectual and sometimes socially awkward side.
To develop their characters further, they could be placed in a cross - cultural investigation. Tony, with his more worldly experience in some ways, and Spencer with his encyclopedic knowledge. They would have to learn from each other and adapt. Tony could learn more about different cultures on a deeper level from Spencer's research, and Spencer could learn how to interact with people in different cultural settings from Tony's practical experience. This would add new layers to their personalities and their relationship.
Perhaps in the fanfic, the OC has a special skill that Reid needs to utilize. However, due to some misunderstandings, he has to handcuff her first. This could lead to a story of them overcoming their differences and working together while the handcuffs become a symbol of their initial conflict and later connection. For example, she might be able to read ancient languages and Reid needs her help with a case involving historical documents.
A third plot idea might be that Tony and Jeanne meet again in a different country while they are both on vacation. They start to explore the local area together and slowly realize that they still have a connection. However, they both have different lives now, and they have to decide if they want to start over or just leave the past in the past.
A plot could involve the OC using their lip - reading to communicate secretly with Reid in a dangerous situation. Like when they are held hostage by a group, and the OC lip - reads the plans of the captors to Reid without the captors noticing. Then there could be a romantic sub - plot where Reid is initially intrigued by this unique skill of the OC and gradually falls for their personality as well. The OC might also be in danger because of their lip - reading ability as someone wants to keep their secrets hidden.
One plot idea could be that they discover their 'brotherhood' through some magical or scientific accident. Maybe they have to team up to stop a common enemy, like an ancient, powerful being. They could start off hating each other because of their different personalities (Tony's brashness vs Loki's slyness), but as they face challenges together, they learn to respect and care for each other.
One interesting storyline could be Tony Dinozzo using his detective skills learned from the military in a civilian crime - solving situation. Maybe he has to use his military training to track down a dangerous criminal who has military - like tactics.