Chicago Med Season 9 Episode 1 spoilers suggest that Dr. Charles will cross paths with someone from his past while the ED crew deals with car crash victims.
Dr. Will Halstead: Okay, who the hell is this guy? EMT: Says he's a doc Dr. Will Halstead: Alright, get off the gurney, doc. I'm senior resident in this ER. Dr. Connor Rhodes: Yeah? Well, I'm your new trauma fellow.