The CW has released the full synopsis for this year’s mega-crossover event, that starts with Supergirl and Arrow on November 27th, and concludes with The Flash and Legends of Tomorrow on the 28th!

Barry (Grant Gustin) and Iris’s (Candice Patton) 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 (Wentworth Miller), The Ray (Russell Tovey), Felicity Smoak (Emily Bett Rickards), Iris West and Alex Danvers (Chyler Leigh) to take on their most formidable villains yet. Earth’s mightiest heroes – Green Arrow (Stephen Amell), Supergirl (Melissa Benoist), The Flash (Grant Gustin) and White Canary (Caity Lotz) – lead their teams into battle to save the world.