Supergirl Season 2 Episode 8

A superhero crossover event begins with Barry Allen and Cisco Ramon from "The Flash" seeking Kara's help with an alien invasion; at the same time, Eliza comes to town to celebrate Thanksgiving with her daughters, which seems like the perfect opportunity for Alex to come out to her mother. Meanwhile, Winn and James consider telling Kara the truth about the Guardian; and Kara wants to team up with Lena Luthor to combat a deadly virus unleashed by CADMUS.