The ninth season of Criminal Minds follows the Behavioral Analysis Unit as they investigate a number of disturbing cases and track down the perpetrators, who include a ritualistic killer in Arizona, a sniper in Dallas who may be using the 50th anniversary of the Kennedy assassination as a motivating factor, a deadly UnSub in Utah with a bizarre fascination with the Salem witch trials, and missing teens in Chicago who commit a series of mass murders. Back at headquarters in Quantico, Va., new section chief Mateo Cruz (Esai Morales) is introduced and it's learned that he has a long work history with JJ (A.J. Cook), who is guarding a secret that could put her life in danger. As for Hotch (Thomas Gibson), he collapses during a meeting and is rushed to the hospital where he fights for his life due to complications from his stabbing at the hands of George Foyet (C. Thomas Howell), the infamous "Reaper," who murdered his wife Hayley (Meredith Monroe). During surgery Hotch sees mysterious visions of both Hayley and Foyet. Elsewhere, Rossi (Joe Mantegna) searches for his former Marine sergeant (Meshach Taylor) when he goes missing; Garcia (Kirsten Vangsness) delves into her hacker past and reconnects with an old flame; and Blake (Jeanne Tripplehorn) experiences a tense reunion with her father and brother, who help her investigate homicides in Kansas City.

As Sookie continues to learn about her supernatural heritage in hopes that she may finally understand, a newly reincarnated Bill struggles to reconcile his former ways with a mysterious set of powers that appear to be both a blessing and a curse from the ancient vampire Lilith. Elsewhere, Louisiana Governor Truman Burrell enacts his plan to rid the vampires from his constituency, and the Stackhouse siblings prepare to confront their parents' killer.