Nikita’s Xander Berkeley guest stars in the Sunday, October 28 episode of Supergirl which gives us the origin of the Agent Liberty character that will be played by Sam Witwer in Season 4.
Here’s the official description with some spoilers courtesy of the network:
XANDER BERKELEY GUEST STARS IN THE ORIGIN STORY OF AGENT LIBERTY — Ben Lockwood (Sam Witwer) didn’t always hate aliens. Through a series of incidents, and input from his anti-alien father (guest star Xander Berkeley), Ben slowly transforms from a mild-mannered professor into the villainous Agent Liberty of today. Jesse Warn directed the episode written by Rob Wright & Derek Simon (#403). Original airdate 10/28/2018
Supergirl returns October 14 with “American Alien” – photos from the season premiere can be found here.