Check out the official "Heroes v Aliens" extended trailer for Supergirl crossover event starring Melissa Benoist, Grant Gustin, Stephen Amell, Candice Patton, Mehcad Brooks, Chyler Leigh and Jeremy Jordan, right now on Fan Reviews!

See Heroes v Aliens on the 4 night crossover event, starting with Supergirl Monday at 8/7c on The CW!

SUPERGIRL is based on the DC character Kara Zor-El, Superman's cousin, who after 12 years of keeping her powers a secret on Earth, decides to finally embrace her superhuman abilities and be the hero she was always meant to be. Kara lives in National City assisting media mogul Cat Grant. However, Kara's days of keeping her talents a secret are over when Hank Henshaw, head of a super-secret agency, enlists her to help protect the citizens of National City from sinister threats.