From the moment it was announced, this year's Arrowverse crossover ("Crisis on Earth-X") has promised to be a big one, and now the storyline's newly-released synopsis makes it seem like an even bigger event.

Typically, The CW releases a different synopsis for each one of its Arrowverse series -- Arrow, The Flash, Supergirl and DC's Legends of Tomorrow -- but for the upcoming four-part event, the network has opted to release a single, longer than normal synopsis, that covers every chapter of the event.

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While much of the synopsis basically recaps details we already know (Barry and Iris are getting married, and while the ceremony is unfolding, a group of nazi-esque villains from another dimension arrive and attack the gathered heroes), it does reveal a few key pieces of new information. Wentworth Miller's back, but not as Captain Cold; rather, he'll be playing Citizen Cold, a heroic version of Leonard Snart from yet another reality. And, it would appear he'll be teammates with The Ray, a new hero that has yet to be introduced on any of the live-action Arrowverse series.

Below, you can check out the full synopsis for "Crisis on Earth-X," which airs from Nov. 27-28 on The CW.

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THE EPIC FOUR-WAY CROSSOVER WITH “ARROW,” “SUPERGIRL,” “THE FLASH” AND “DC’S LEGENDS OF TOMORROW” BEGINS — Barry (guest star Grant Gustin) and Iris’s (guest star 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 (guest star Wentworth Miller), The Ray (guest star Russell Tovey), Felicity Smoak (guest star Emily Bett Rickards), Iris West and Alex Danvers (Chyler Leigh) to take on their most formidable villains yet. Earth’s mightiest heroes – Green Arrow (guest star Stephen Amell), Supergirl (Melissa Benoist), The Flash (guest star Grant Gustin) and White Canary (guest star Caity Lotz) – lead their teams into battle to save the world. Larry Teng directed the episode with story by Andrew Kreisberg & Marc Guggenheim and teleplay by Robert Rovner & Jessica Queller (#308). Original airdate 11/27/2017.

This year’s four-part Arrowverse crossover will air on The Cw across two nights, beginning Monday, Nov. 27, with Supergirl and Arrow (on a special night for one week only), and concluding Tuesday, Nov. 28 with The Flash and DC's Legends of Tomorrow.