A promo for the upcoming Supergirl episode "In Plain Sight" teases J'onn's evil brother Malefic becoming an even bigger threat than before as he shares a psychic link with Kelly Olsen, allowing him to put thoughts into her head.
Kara will also tap into her suspicions and find out what her professional rival William Dey is up to. However, she may find much more to Dey's plans than she anticipated, leading viewers to wonder what danger lurks behind this mysterious character.
Here is The CW's official synopsis for the episode:
SAYING GOODBYE IS HARD TO DO – Kara’s (Melissa Benoist) investigation into William Dey’s (Staz Nair) “criminal” activities results in the shocking revelation he is not who she thinks. Meanwhile, the conflict between Malefic and J’onn J’onzz (David Harewood) reaches a boiling point. David McWhirter directed the episode written by Jay Faerber & Jess Kardos.
In the most recent episode, it was revealed that Lena was seeking to use Q waves to rewrite humans' brains, prohibiting actions like lying and violence, and she was able to persuade Supergirl to take Lex Luthor's journals so she could study his work and overcome a technological barrier she came across. This cliffhanger was not addressed in the "In Plain Sight" promo, but it's certainly an interesting thread to be potentially explored in the episode.
Airing Sundays at 9 p.m. ET/PT on The CW, Supergirl stars Melissa Benoist as Kara Danvers, David Harewood as Martian Manhunter, Mehcad Brooks as Jimmy Olsen and Chyler Leigh as Alex Danvers.