Supergirl 3×06 “Midvale” Season 3 Episode 6 Sneak Peek – Kara (Melissa Benoist) and Alex (Chyler Leigh) head home to Midvale for a little R&R. While there, Kara recalls a painful memory of a childhood friend’s death and how that traumatic experience brought the Danver sisters closer together. Izabela Vidovic plays Young Kara and Olivia Nikkanen plays Young Alex in flashbacks. Rob Greenlea directed the episode written by Caitlin Parrish and Jess Kardos (#306). Original airdate 11/13/2017.