Over the past many seasons, Supergirl has been busy grappling with the troubles created by Lex Luthor but we haven’t seen Lex on screen yet. But it seems we are about to see him being featured in season four finale episode in which the Girl of Steel will have one last shot to prevent Lex from causing mayhem and perhaps save her own reputation along with it. 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 (#422). The CW has released a promo for The Quest for Peace next week’s Season four finale episode of Supergirl. The episode is a derivation of Superman IV: The Quest For Peace, the 1987 movie which featured Jon Cryer who plays Supergirl’s Lex Luthor as Lenny Luthor, the villain’s nephew. Supergirl airs on Sunday nights at 8 p.m. ET/PT, before episodes of Charmed on The CW. The Quest For Peace will debut on 19 May 2019.