‘Crisis on Earth-X’ key art
Villains from Earth-X crash Barry (Grant Gustin) and Iris’ (Candice Patton) wedding in this year’s four-way crossover between “Arrow,” “The Flash,” “Supergirl” and “Legends of Tomorrow.” The CW

Barry and Iris are set to tie the knot in this year’s four-way crossover between CW’s “Arrow,” “The Flash,” “Supergirl” and “Legends of Tomorrow.”

According to the official logline for the crossover, entitled “Crisis on Earth-X,” all of the superheroes come to Central City for Barry (Grant Gustin) and Iris’ (Candice Patton) wedding. However, villains from Earth-X crash the festivities with a deadly agenda.

Earth-X is a parallel Earth, where Germany won World War II and Green Arrow, The Flash and Supergirl are evil. Earth-X is featured in the upcoming animated CW Seed series “Freedom Fighters: The Ray.”

“We conceived this year’s crossover to be evocative of the annual Justice League/Justice Society crossovers we grew up with and looked forward to as kids,” said executive producers Marc Guggenheim and Andrew Kreisberg in a statement.

To mark the special event, which started production on Friday, The CW and Warner Bros. commissioned legendary Wonder Woman artist Phil Jimenez to create a custom cover for the crossover.

“Phil was the perfect choice to bring the comic book cover iteration of this idea to life,” Guggenheim and Kreisberg said. “You can count on one hand the number of artists who could compellingly represent so many characters in a single image. Phil is one of them. And his design invokes the cover of Justice League #207, which was the 20th Annual JLA/JSA crossover. Our ten-year-old selves are in heaven.”

As seen in the poster below, it seems that Barry, Oliver (Stephen Amell) and Kara (Melissa Benoist) will be facing off against evil versions of themselves. It’s likely that Gustin, Amell and Benoist will also play their Earth-X doppelgangers as Benoist was tapped to voice Overgirl — Supergirl’s Earth-X counterpart — on “Freedom Fighters: The Ray.”

Kreisberg first revealed that Barry and Iris will finally get married in an interview with Entertainment Weekly earlier this month. While the wedding is definitely good news for WestAllen fans, Kreisberg pointed out that the nuptials doesn’t guarantee a happy ending for the couple. “It’s going to be: Can they stay married with everything that’s coming up against them?” Kreisberg teased.

The crossover will air across two nights, beginning with “Supergirl” and “Arrow” on Monday, Nov. 27 at 8 p.m. EST, and concluding with “The Flash” and “Legends of Tomorrow” on Tuesday, Nov. 28 at 8 p.m. on The CW.