Next Sunday, Supergirl Episode Name “The Quest for Peace” Will be The Last Episode of Season 4 Which air on May 19, 2019 ,The CW (8:00-9:00 p.m. ET)
In this episode – LEX LUTHOR RETURNS — Lex Luthor (guest star Jon Cryer) descends upon Washington, DC and summons Lena (Katie McGrath) and Lillian Luthor (guest star Brenda Strong) to the White House. Supergirl (Melissa Benoist) realizes she has one last chance to stop Lex and turns to the power of the press to help her.
Jesse Warn directed the episode with story by Robert Rovner & Jessica Queller and teleplay by Rob Wright & Derek Simon