The CW has released the official synopsis for "Crisis on Infinite Earths, Part One," the December 8 Supergirl episode that will serve as the kick-off to the five-part crossover epic that will change the face of the Arrowverse. The episode will see the heroes of Earth-1 travel to Earth-38 (where Supergirl takes place) in order to save her world from the wave of antimatter coming from the Anti-Monitor. Little is known about the story in individual episodes, although it is likely that fans will know a little bit more by the time the episode airs, considering the presence of The Monitor on Arrow and The Flash this season.
The episode is based on a story by showrunner Robert Rovner and "Crisis" event showrunner Marc Guggenheim, and features a teleplay by Derek Simon and Noble Causes creator Jay Faerber.
THE KICKOFF TO THE EPIC TELEVISON CROSSOVER EVENT, CRISIS ON INFINITE EARTHS - The Monitor (guest star LaMonica Garrett) sends Harbinger (guest star Audrey Marie Anderson) to gather the worlds’ greatest heroes - Supergirl (Melissa Benoist), The Flash (guest star Grant Gustin), Green Arrow (guest star Stephen Amell), Batwoman (guest star Ruby Rose), White Canary (guest star Caity Lotz), The Atom (guest star Brandon Routh) and Superman (guest star Tyler Hoechlin) - in preparation for the impending Crisis. With their worlds in imminent danger, the superheroes suit up for battle while J’onn (David Harewood) and Alex (Chyler Leigh) recruit Lena (Katie McGrath) to help them find a way to save the people of Earth-38. Jesse Warn directed the episode with story by Robert Rovner & Marc Guggenheim and teleplay by Derek Simon & Jay Faerber.
"Crisis on Infinite Earths" has loomed over the Arrowverse for years. The series premiere of The Flash featured an allusion to the hero disappearing amid red skies in the year 2024. During the original comics event, red skies were a sign of doom to come to a world during the Crisis. At the end of last season, a couple of things happened: The Monitor (LaMonica Garrett), who had appeared in "Elseworlds," reappeared and revealed that Oliver Queen was destined to die in the Crisis...and the future newspaper at STAR Labs rolled back the expected date of the Crisis from 2024 to 2019.
In the comics, Crisis on Infinite Earths centered on a battle between the combined superheroes (and even some villains) of the DC multiverse and an immortal, cosmic threat known as the Anti-Monitor. Like The Monitor, the Anti-Monitor will be played by LaMonica Garrett in the Arrowverse. As the Anti-Monitor destroys realities, he replaces their positive matter energy with antimatter, growing his own power and sphere of influence. He was eventually stopped by the sacrifices of several heroes, including The Flash and Supergirl, as well as the merging of multiple universes to save reality by becoming a single, unified timeline. Fans have long wondered whether the events of "Crisis on Infinite Earths" might bring Supergirl and even Black Lightning to Earth-1, where the rest of the series take place. The crossover will also feature guest appearances by Tom Welling as Clark Kent, Erica Durance as Lois Lane, John Wesley Shipp as the Flash of Earth-90, Johnathon Schaech as Jonah Hex, Kevin Conroy as Bruce Wayne, and Ashley Scott as The Huntress.
“Crisis on Infinite Earths” kicks off on Sunday, December 8 on Supergirl, runs through a Monday episode of Batwoman and that Tuesday’s episode of The Flash. That will be the midseason cliffhanger, as the shows go on hiatus for the holidays and return on January 14 to finish out the event with the midseason premiere of Arrow and a "special episode" of DC's Legends of Tomorrow, which launches as a midseason series this year and so will not have an episode on the air before the Crisis.
Disclosure: ComicBook is owned by CBS Interactive, a division of ViacomCBS.