A crossover could involve a character from Chicago Fire having a personal connection to a case the Chicago PD is working on. Maybe a firefighter's family member is wrongly accused of a crime. The firefighter then teams up with the PD detectives to clear their family member's name. This would bring in elements of loyalty, family, and the different skills of both groups. They could share information and resources to solve the mystery.
Well, the plot could start with the immediate aftermath of Erin getting shot. There'd be chaos at the scene, her colleagues in shock. Then it might focus on the investigation into who shot her. Maybe it was a criminal she put away who had connections on the outside and arranged for the hit. The story could also involve her struggle in the hospital, dealing with pain and the fear of not being able to return to work.
One great 'chicago pd fanfic' is 'The Blue Line Bonds'. It delves deep into the relationships between the characters outside of their regular work scenarios. The character development is on point and it gives a fresh perspective on the show's dynamics.
A common plot point is the emotional reaction of her colleagues. Voight, for example, would be extremely protective and angry that one of his team members was hurt. He might go on a personal vendetta against those responsible. Another point could be Erin's own struggle while recovering. She might be impatient to get back to work and frustrated with her physical limitations.
There's a possibility that it's a family member of a criminal she arrested. They might be seeking justice in their own twisted way. They could have been planning the attack for a long time, waiting for the perfect moment to strike when Burgess was most vulnerable. Another suspect could be a corrupt cop from another precinct who doesn't like the way Burgess and her team are cleaning up the streets and cutting into their illegal activities.
Her colleagues would be very concerned. Voight, as her boss, would probably be angry at the situation that led to her getting hurt and determined to bring those responsible to justice. Jay would be extremely worried and would likely stay by her side at the hospital as much as he could, constantly checking on her condition.
Well, it is. 'Chicago PD' takes elements from real - world happenings within the Chicago Police Department. They might fictionalize some aspects for the sake of drama, but at its core, it's rooted in the true nature of police work in Chicago. For example, the types of crimes they deal with and the general environment are reflective of the real city.
A fanfic could focus on Voight's backstory. Maybe he has an old case that resurfaces, and he has to deal with the ghosts of his past while still leading his team. It could show his vulnerability and determination in the face of personal and professional difficulties.