I was watching Castle while doodling, and this happened. Basically I created the Castle!AU just because the main characters really remind me from Frozen characters.
Anna is enthusiastic mystery novelist who follows homicide detective Elsa in her work to get some inspiration for her books. Elsa is so strict that the idea and Anna’s actions annoys the frick out from her most of the time. Kristoff is in Elsa’s team under her command, alongside with Hans. Both men like to see Anna goofing around and Elsa getting mad at her.
Anna is excited because the murder scene is so absurd. I really don’t remember the case though…