Criminal Minds and The X-Files Crossover

I decided to write a Criminal Minds and The X-Files crossover. I will be taking liberties. Some characters may not exist and certain plots may not have happened. Most of the main characters from both shows are the same, though.

Lisa Heathers is twenty nine years old when she is transferred out of the BAU and into the X-Files unit. Her and her boyfriend, BAU Unit Chief Aaron Hotchner, end up having a lot of problems because of this. And Lisa wonders which is more difficult: catching serial killers with the BAU or working on the X-Files?

(In this story, Hotch was never married and doesn't have a son. So the story arc with The Reaper never happened. I have no idea if people on the same team are actually allowed to date but in this story they do. Also, Hotch is six years older than Lisa.)