Photo: The CW

While we anxiously await the fall premieres of The CW’s Arrowverse series (a few weeks and counting!), we finally get to learn a tad more about this year’s crossover episode with a casting update.

The CW previously announced the three-part episode, titled “Elseworlds,” will introduce Ruby Rose’s Batwoman and Gotham City to the Arrowverse squad. The CW also revealed a new tagline, “Chaos is coming.”

The three-part crossover will span The Flash, Supergirl, and Arrow, but not Legends of Tomorrow this year. Already announced, part of the story involves Dr. John Deegan’s attempts at Arkham Asylum to draw the Flash, Green Arrow, and Supergirl to Gotham City. The three-night event will bring back Tyler Hoechlin’s Superman, as well as Lois Lane (Elizabeth Tulloch) and Nora Fries (Cassandra Jean Amell) to help the superheroes.

Additionally, LaMonica Garrett (Designated Survivor) joins the special three-part episode in a prominent role as the DC Comics character The Monitor, AKA Mar Novu, who is an extraterrestrial being of infinite power.

In the “Crisis on Infinite Earths” comics, created by Marv Wolfman and George Pérez, The Monitor was an alien tasked with watching over the multiverse, which was threatened by the villain Anti-Monitor. Then, later DC crossovers introduced an entire organization of multiversal Monitors. Additionally, The CW announced that Pérez will illustrate a sketch of the Monitor that will play a significant role in the episode’s story.

Photo: DC Entertainment

While no specific plot details about this year’s Arrowverse crossover have been revealed, since it is titled “Elseworlds” and features the Monitor, that could suggest that the multiverse is in danger (I know, what a shock for the superhero shows).

In the comics, Elseworlds was a term typically used to classify “what if” stories that took place outside of DC continuity, such as “Kingdom Come” and “Superman: Red Son,” in which the latter serves as inspiration for part of the new season of Supergirl (hello, season three finale!), so it will be interesting to see how the Elseworlds connects to our dear DC heroes.

This year’s crossover event begins Sunday, December 9 with The Flash at 8pm and continues that following Monday with Arrow, and wraps up with Supergirl on Tuesday.

h/t Entertainment Weekly