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 band together with help from their super friends like Citizen Cold, The Ray, Felicity Smoak, Iris West and Al... (more)ex Danvers 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. Part 1 - Supergirl - S03E08 Part 2 - Arrow - S06E08 Part 3 - The Flash - S04E08 Part 4 - DC's Legends of Tomorrow - S03E08

Candice Patton, Carlos Valdes, Christina Brucato, Chyler Leigh, Danielle Panabaker, David Ramsey, Echo Kellum, Emily Bett Rickards, Grant Gustin, Juliana Harkavy, Melissa Benoist, Rick Gonzalez, Russell Tovey, Stephen Amell, Tom Cavanagh, Wentworth Miller