The doctor in the flashback is a younger version of Dr. Arden from "Asylum", making this the third season-to-season crossover in the series. John Cromwell plays the younger doctor and is the son of James Cromwell who played Dr. Arden is "Asylum". Prior to this character cross-over, there was Naomi Grossman as Pepper and Lily Rabe as Sister Mary Eunice McKee.
Elsa (Jessica Lange) tells the freaks they are going to watch a movie as a celebration and Legless Suzi (Rose Siggins) says "Not 'Sign of the Cross' again." In "Asylum", Sister Jude (also played by Jessica Lange) has the asylum patients watch The Sign of the Cross (1932) to distract them from a storm.
Oddly, Chester Creb's (Neil Patrick Harris) U.S. Army uniform does not have a Purple Heart ribbon, which is awarded for being wounded in combat. It does show he was a soldier with the 1st Infantry Division who received a Bronze Star. It is unknown if this was an oversight by the costume designer, or if Creb lied about receiving a serious head wound to account for his growing insanity.