Season three saw the hero stop Reign and the other Worldkillers' threat to the planet, and in the process, Kara discovered her mother survived the destruction of Krypton. Reconnecting with her past caused Kara to realise that her true home is on Earth, where big changes are taking place for her and all her friends in National City, and also, it appears, for a doppelganger in Russia. With a wave of anti-alien sentiment roiling the country led by Agent Liberty and a new command at the DEO, Colonel Haley, Kara returns to Catco, where she mentors young reporter Nia Nal, who evolves into a superhero herself. Season four promises to be full of surprises, action, adventure and lots of big revelations for Supergirl.