"She's going to be the oldest grandmother in the world if I don't hurry up!
Prentiss and Todd may have uncovered a key piece of of puzzle when they track who they suspect of being the killer's teacher.
“Criminal Minds” also stars Joe Mantegna, Paget Brewster, Matthew Gray Gubler, A. Cook, Aisha Tyler, Kirsten Vangsness, Adam Rodriguez and Damon Gupton.
Executive producers are Mark Gordon, Erica Messer and Breen Frazier.
This case also tests the new working relationship between Todd and Hotch.
Season 4 is a very strong contender for the best season of ' Criminal Minds'.