When the BAU investigates victims of possible ritualistic murders in Utah, clues lead them to believe that they are looking for a serial killer who holds a deep fascination of the Salem witch trials. Also, Garcia prepares for a "Day of the Dead" celebration over at her apartment.
- John Lee Ames - Parker Mills
- Caitlin Carmichael - Kylie Carpenter
- Peggy Dunne - M.E. Linda Grunwell
- Jeff Griggs - Herbert Sykes
- James Immekus - Leland Duncan
- Tom Irwin - Sergeant Joe Mahaffey
- Aubrey Manning - Charlotte Novak
- Sarah Jane Morris - Yvonne Carpenter
- Charlotte Ubben - Gloria Carlyle
- Spencer Reid: "After all, what are men but a horde of ghosts? Oaks that were acorns that were oaks." — Walter de la Mare
- Penelope Garcia: Mitch Albom said, "Death ends a life, not a relationship."
- Caitlin Carmichael, the actress who portrays Kylie Carpenter, previously appeared on Criminal Minds, starring as Louisa Bonner in the Season Four episode "Roadkill".
- Three of the names seen on Garcia's list of Salt Lake City, Utah library personnel, were previously used by the following victims:
- Season Seven
- Season Eight