Supergirl had double duties this week as not only was it time for Kara Zor-El’s second winter finale, but also setting up the 4-show crossover with The Flash, Arrow and Legends of Tomorrow. It’s Thanksgiving over in National City as Mama Danvers is visiting and Mon-El experiences his first Thanksgiving. Meanwhile Winn, Alex and James are arguing about when Kara will get to find out who Guardian actually is.
Dinner gets interrupted by a multidimensional breach from Earth-1 which keeps popping up a few times throughout the episode. Kara reaches out to Lena Luthor to find out if she knows what her mother is up to, with Project Cadmus. Lena reaches out to her mother and their backstory is heavily explored which helps explain more of their current relationship.
However, Cadmus is already causing trouble as Cyborg Superman attacks the Alien Club and gets Mon-El infected by a dangerous gas which is revealed to be Project Medusa that can kill any alien. J’onn’s condition is also getting worse with the White Martian blood beginning to take over and he accidentally exposes his secret to Kara. On the subject of secrets, Alex comes out to her mother about her sexuality and Eliza shows her enormous support.
As Supergirl tries to reason with Lena, the Luthor daughter makes it clear that she stands by her mother’s side. With the Luthors getting ready to expose Medusa to all the aliens in National City, J’onn and Kara show up and confront them and Cyborg Superman. While the virus is unleashed, it is revealed that Lena switched out the isotopes so that the one that went out instead healed all aliens, including J’onn. While Lillian is stopped, new threats are teased.
Kara returns to her apartment where she finds Barry Allen and his friend Cisco Ramon from Earth-1 popping up through a breach, as they need her help on their Earth. With so much happening in this incredibly packed episode, there’s a lot that we want to break down and discuss. So let’s go through the top 5 highlights and important moments of the Supergirl Season 2 episode: “Medusa”