Synopsis

The wedding of Barry and Iris unites the heroes, but the celebration is shattered by an attack from villains of Earth-X. United, the superheroes rally with the aid of allies like Citizen Cold, The Ray, Felicity Smoak, Iris West, and Alex Danvers, facing their most dangerous adversaries yet. Green Arrow, Supergirl, The Flash, and White Canary lead Earth’s greatest champions into battle to safeguard the world. The crossover event continues in "Crisis on Earth-X (II)" (Arrow S06E08), "Crisis on