In Supergirl S03E06: Midvale, Back to Midvale High School, Alex & Kara have a mutual friend, she is murdered by her teacher, after effort on killing them failed, the teacher was arrested. But they also found out that someone who is drug dealer in accusing for killing their’s friend.

Supergirl S02E14, When Jeremiah Danvers is rescued from Cadmus, Alex and Kara are thrilled to have him back, but Mon-El is suspicious about his sudden return.