A few days ago, some promo images were released for the next episode of Supergirl (entitled Luthors) as well as a quick plot synopsis of the episode.
After Metallo (guest star Frederick Schmidt) breaks out of prison and frees Lillian Luthor (guest star Brenda Strong), the police blame Lena (guest star Katie McGrath) for his escape and arrest her. Despite overwhelming evidence, Kara (Melissa Benoist) refuses to believe her friend is guilty and fights to clear Lena’s name. Flashbacks reveal how Lena came to be a Luthor. Meanwhile, Alex (Chyler Leigh) introduces Maggie (Floriana Lima) to the gang. Tawnia McKiernan directed the episode written by Robert Rovner and Cindy Lichtman.
So, here we have Lena finally return to the show, as well as Metallo, and Lillian (and we assume CADMUS as well). We also will get some insight into what happened with Lena and how she became part of the evil Luthor family. Some promo images reveal James getting injured (we assume as Guardian), some Snapper images (as we also assume Kara goes after the story for CatCo), and some images involving Lena and Lillian.
