- Tacey Adams - Medical Examiner
- Christopher Boyer - Shop Manager
- Joanne Casey - Phyllis
- Megan Duffy - Cindy Amundson
- Dan Ernst - Bob Stuart
- Jonathan Frakes - Doctor Arthur Malcolm
- Jennifer Hasty - Samantha Malcolm
- Jeffrey Johnson - Detective Marty Cotrone
- Butch Klein - Marc
- Gregory Marcel - Karl Wallace
- Anna Moore - Mary Newsome
- Matthew Moy - Eric
- Patrick O'Connor - Doctor Finn
- Monique Patrice - Maxine Wynan
- Leonard Robinson - Joe
- Andy Rolfes - Don
- Valeri Ross - Linda Jackson
- Rosalie Ward - Bethany Wallace
- Genene Jones
- Amy Archer-Gilligan
- Spencer Reid: Mildred Lisette Norman wrote, "Anything you cannot relinquish, when it has outlived its usefulness, possesses you. And in this materialistic age, a great many of us are possessed by our possessions."
- Spencer Reid: Isaac Asimov wrote, "In life, unlike chess, the game continues after checkmate."
- The title is a reference to the uncanny valley, a hypothesis in the fields of robotics and 3D animation. It postulates that there comes a point when human replicas act and look so similar to real humans that the latter becomes uncomfortable around the former. The term refers to a graph that shows how human feelings of familiarity towards anthropomorphic robots or robotic parts (including prosthetics) becomes lower the more life-like they seem. The use of it as a title refers to the unsub's obsession with dolls.