Kim Burgess (Marina Squerciati) is in an interesting spot. The tenth season of Chicago PD will go down as one of the character's most important, between her promotion to detective and wedding to Adam Ruzek (Patrick John Flueger), but in truth, she hasn't had much to do.
The character has spent most of the season in supporting character mode, whether it be during the One Chicago crossover event or the storyline involving Ruzek's dad, Bob (Jack Coleman). Thankfully this will change in the March 26 episode of Chicago PD.
Burgess' PTSD seemingly resurfaces
The promo for the episode sees Burgess take lead on a crime that takes place at her favorite diner. She recognizes the victims as fellow regulars at the diner, but struggles to determine what the cause could have been or who the culprit could be. "You notice a lot, Kim, you just have to remember," Adam Ruzek tells her.
Burgess has a keen eye when it comes to investigating, hence her recent promotion, but she has also struggled when it comes to retaining information in traumatic situations in which she has a personal stake. Lest we forget, Burgess led the season 10 episode "Memory," in which her reaction to a gnarly cold case led to concern about her mental health.
The detective was shot and nearly killed in the line of duty in season 8, and the PTSD she suffered as a result took a massive toll on her personal and professional life. She would be overcome with stress in the field, and effectively shut down. She eventually went to therapy, where she was able to identity and overcome the cause of her trauma. At least, for the most part.
The character has overcome a lot in recent seasons

In real life, trauma of that magnitude does not simply disappear. People have relapses, have episodes in which certain events will trigger its effects. Chicago PD writers did an excellent job of carrying this through line through multiple seasons, but season 12 has been oddly bereft of it.
Burgess may be stronger, but the notion of a place she frequents and feels safe being the scene of a grisly crime would be more than enough to cause psychological discomfort and make it tough for her to easily pick out clues. We've no doubt that she will overcome, and get the job done in time to catch the perpetrator, but we appreciate the attention paid to her character and a storyline that has been mostly ignored in recent seasons.