Crisis On Earth X

Four-episode crossover event featuring DC superheroes from 'Arrow', 'The Flash', 'Supergirl' and 'DC's Legends of Tomorrow'. During the wedding of Barry Allen (Grant Gustin) and Iris West (Candice Patton), the ceremony is invaded by villains from Earth-X, led by Dark Arrow (Stephen Amell) and his wife Overgirl (Melissa Benoist). Green Arrow (Amell), Supergirl (Benoist), The Flash and White Canary (Caity Lotz) are joined by the Legends of Tomorrow as Earth's heroes band together in an attempt to stop their enemies from destroying the world as they know it.