When you have a whole multiverse to play with, death is never finite. That’s the Arroverse credo, and it’s one that will put us back in touch with Captain Cold, Reverse Flash, and Prometheus during The CW’s annual DC crossover.

The heroes of “The Flash,” “Arrow,” “Legends of tomorrow,” and “Supergirl” have each other’s backs like no other, but how will they fair when they have to root out their own Nazi doppelgangers?

That’s the question “Crisis on Earth X” will ask, and it’s one we can start to answer with a few recent set photos.

'Legends of Tomorrow' Battle Familiar Faces

Key art for the four-episode event placed the leads up against some serious firepower. From a Dark Arrow to Overgirl to a Dark Flash, the upcoming villains of The CW Seed’s “Freedom Fighters: The Ray” will get a little live action intro before they slip into animation. They won’t be alone, however. In a world where the Nazi’s won WWII (we won’t get into how at the moment), Prometheus will join up with the Third Reich while the Dark Flash will take a backseat to the perennial Reverse Flash.

While Dark Arrow, Overgirl, and Prometheus have yet to be unmasked, fans have pulled back Reverse Flash’s cowl to reveal none other than Harrison Wells (Tom Cavanagh). Is this Earth X’s real Dr. Wells? Is it Eobard Thawne masquerading as the famed scientist? Considering how many iterations of Cavanagh’s character we’ve seen, it’s not hard to imagine a world in which the inventor finds himself allied with the embodiment of evil.

Check out Grant Gustin (The Flash) and Cavanagh standing by as the non-speedsters film their battle against the SS. Just as Overgirl bears the double lightning bolts of the Schutzstaffel where her family’s “stronger together” motto used to shine, Reverse Flash will have the double lightning bolts emblazoned on his suit as well.

Promethious, meanwhile, will wear the armband.

Why Will Captain Cold Return To 'Legends'?

What we don’t know, however, is which side Captain Cold/Leonard Snart (Wentworth Miller) will take. Killed off during season 1 of “Legends of Tomorrow,” the beloved hero/villain made occasional appearances throughout season 2. It’s unknown how long Cold will stick around this time, or if he’ll even remember his old pals.

“It will be about as polar opposite as the Snart that he’s played on our show,” executive producer Phil Klemmer told DC Legends TV. “We’ve got a cool pitch to justify that version of him, which I don’t want to give away.”

Find out more when “Legends of Tomorrow” airs Mondays at 9 p.m. ET on The CW.