Dr. Will Halstead left Chicago Med at the end of Season 8 after deliberately sabotaging a new AI-assisted operating room system to expose its dangerous flaws that had already caused a patient death. He resigned from his position accepting responsibility for the incident to prevent others from being blamed. His departure allowed him to reconnect with his ex-fiancée Natalie, giving his storyline a heartfelt send-off. The actor Nick Gehlfuss said in interviews that he left the show because he felt he had taken the character as far as he could creatively and wanted to explore new roles. He also left the door open for potential future appearances if it made sense creatively.
