The ninth season of Criminal Minds tells the story that happened three months later, when Morgan (who went to London to perform the Olympic security mission) and Garcia (who helped Prentiss move into a new home) returned from the UK and found that there was one more person around them - Alex Blake, a linguistics expert who has worked for the FBI for a long time, officially joined the BAU investigation team. Alex is fearless and once caused a stir in the city because of the conflict with Strauss. Garcia was not optimistic about this new woman, but Alex's superb skills eventually changed her mind. This is a good thing - the BAU investigation team must understand the truth that "unity is strength", otherwise they will not be able to face the new threats of this season. At the end of the first episode, the audience will see that a certain villain has not only been mocking them, harassing them, but even hunting them. It was not until the season finale of this season that the BAU investigation team had the opportunity to confront this cunning and fierce opponent head-on.