Over its impressive 15-season run on the air, Criminal Minds introduced a bevy of fascinating characters and villains, but who was The Black Queen, and why were they important? Criminal Minds debuted in 2005 and put a clever spin on the classic procedural formula by telling the story of the FBI's elite Behavioral Analysis Unit which catches notorious serial killers. As such, many of the show's most gripping episodes were ripped from the pages of true crime history and told darker and more frightening stories than most procedurals dared to do. Even so, Criminal Minds never neglected its main characters, and each had a strong arc throughout the series.

https://screenrant.com/criminal-minds-black-queen-explained/