Barry and Iris's wedding brings the gang together, but things go awry when villains from Earth-X attack the ceremony. All of the superheroes join forces to take on their most formidable villains yet. Earth's mightiest heroes–Green Arrow, Supergirl, The Flash and White Canary–lead their teams into battle to save the world.Supergirl
At 24, Kara Zor-El decides the time has come to embrace her superhuman abilities and fulfill her destiny as a hero.
Barry and Iris's wedding brings the gang together, but things go awry when villains from Earth-X attack the ceremony. All of the superheroes join forces to take on their most formidable villains yet. Earth's mightiest heroes–Green Arrow, Supergirl, The Flash and White Canary–lead their teams into battle to save the world.Kara investigates a secretive new group whose leader, Thomas Coville, has a mysterious connection to Supergirl.Eliza throws Alex and Maggie a wedding shower, which causes Maggie to reach out to her estranged father.Psi, a thief with psychic powers, attacks National City and is able to immobilize people by tapping into their worst fears.A suburban couple's lives are rocked by the discovery that their children possess mutant powers, forcing the family to go on the lam from a hostile government and seek help from an underground network of mutants.Supergirl challenges Rhea to battle to save National City. Meanwhile, Superman returns and Cat Grant offers Supergirl some sage advice.The story of a missing woman named Izzy moves Kara to investigate, even though Snapper Carr has told her to leave the matter alone.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.The Guardian makes his debut in National City to lend a hand after a parasite alien drains Supergirl of her power; at the same time, Mon-El considers a less-than-desirable career change; and Alex struggles with a new reality.Supergirl ends up seriously injured during an attack on National City by a kryptonite-powered villain; and Superman puts the blame for his cousin getting hurt on Hank, because the kryptonite was stolen from the DEO.