Supergirl (2015)

S3E12 For Good

Morgan Edge narrowly escapes an assassination attempt and immediately blames Lena, swearing to ruin her life. Lena, worried that her resentment toward Morgan might lead her down a dark path like the Luthors, seeks Kara’s support. Meanwhile, Sam starts to notice she's experiencing memory lapses and confides in Alex. Concerned for her new friend, Alex takes it upon herself to conduct medical tests to uncover the truth behind Sam's troubling situation.