Alongside Melissa Benoist, who stars in the title role, principal cast members Mehcad Brooks, Chyler Leigh, Jeremy Jordan, and David Harewood return from the first season, and are joined by Chris Wood, Floriana Lima, and Katie McGrath.
At the Fortress of Solitude, Kara learns that Henshaw was after "Medusa", a virus created by her father, Zor-El, to kill non-Kryptonians in case of alien invasion.
Kara and J'onn confront the Luthors and Henshaw before Medusa is disseminated via rocket launcher.
J'onn fights Henshaw, becoming a White Martian, while Kara chases the rocket, which explodes and disperses Medusa.
They find and capture Lyra, who reveals that her brother, Bastian, owes a large sum to a smuggler named Mandrax.
On May 12, 2016, Warner Bros. Television announced that Supergirl had been renewed for a second season of 22 episodes and would move to The CW from CBS.
[55] In the second season, Kara Danvers / Supergirl and James Olsen end their romantic relationship, in favor of maintaining a platonic one.
[58] Kriesberg said another theme of the season was "about coming into one's own and becoming who you are", such as Winn Schott becoming who he is by joining the Department of Extranormal Operations (DEO), and J'onn J'onzz embracing his Martian Manhunter persona, which he spent 300 years concealing, but does not have to any longer.
[61] Melissa Benoist, Mehcad Brooks, Chyler Leigh, Jeremy Jordan, and David Harewood return from the first season as Kara Danvers / Supergirl, James Olsen, Alex Danvers, Winn Schott and J'onn J'onzz / Martian Manhunter, respectively.
[66] With the move of production to Vancouver, it was unclear if Calista Flockhart, who played Cat Grant in the first season, would remain with the series, as her original contract stipulated that she work near her home in Los Angeles.
The CW president Mark Pedowitz said Flockhart wanted to remain with the series and that "We're in ongoing discussions... we're happy to have her in [in whatever capacity] works out.
[55] Kriesberg explained that it "would've started to feel very small" if production had continued in Los Angeles, and that they chose to relocate to Vancouver to shoot in its outdoor locations, rather than continue facing the constraints of shooting mainly inside the studio at Los Angeles.
[75] The episode "Medusa" ends with a scene where Barry Allen and Cisco Ramon of Earth-1 arrive at Kara's loft enlisting her help with a problem on their Earth, thereby setting up the Arrowverse crossover event "Invasion!"
Kara/Supergirl appears in all three episodes as a visitor to their universe due to Supergirl being set in a different Earth, referred to as Earth-38 by the inhabitants of the Arrowverse, and has been informally referred to as "Earth-CBS" by Arrow showrunner Marc Guggenheim, named for the network where Supergirl first aired.
The site's consensus reads, "The arrival of the more famous cousin in Supergirl does nothing to detract from the show's lead, who continues to deliver strength, action, and relatability.
"[104] Metacritic, which uses a weighted average, assigned a score of 81 out of 100 based on 4 reviews, indicating "universal acclaim".
This season not only looked better, it managed to blend epic superhuman conflicts with very real, authentic character drama and a status quo marked by plenty of anti-alien sentiment in National City.
And while the season as a whole had more good elements than bad, the final trio of lackluster episodes managed to end the year on a real down note.
Melissa Benoist still does a fantastic job of portraying "the Girl of Steel," but we are hitting Smallville-levels of drama with the rest of the characters".