At least one mystery has been solved about The CW's upcoming Arrowverse crossover, "Crisis On Earth-X": the identity of the evil Flash from the parallel world.

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New photos from the sent of the event, which pits the heroes of Arrow, The Flash, DC's Legends of Tomorrow and Supergirl against their Nazi doppelgangers, reveals The Flash of Earth-X is played by none other than actor Tom Cavanagh.

Guess who's back?! #TheFlash #ReverseFlash #LegendsOfTomorrow #crossover @WhatsFilming @yvrshoots @olv @CavanaghTom pic.twitter.com/48r8Ijo8av— Suffering Sappho (@ThemysciraBound) October 17, 2017

Photos from the set of the Arrowverse crossover event have revealed that the Flash of Earth-X will be played by Tom Cavanagh, shown wearing the familiar Reverse Flash costume. The speedster from the parallel world where the Nazi's won World War II was previously seen only in artist Phil Jimenez's poster for the event, leaving the character's identity in question.

If Cavanagh is playing Earth-X's Flash, then that would suggest the Harrison Wells of that world became a metahuman. Cavanagh's Wells was a scientist who was killed and replaced by Eobard Thawne (Matt Letscher). Cavanagh has since played various alternate versions of Wells, including Earth-2's Harry Wells and Earth-19's H.R.

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This two-night crossover will see the wedding of Barry Allen and Iris West disrupted by the arrival of the villains from Earth-X. The event will also mark the debut of Russell Tovey as The Ray, ahead of the December premiere of the animated Freedom Fighters: The Ray, in which he'll voice the DC Comics hero.

The four-part crossover will air across two nights on The CW, 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 Legends of Tomorrow.

(via Screen Rant)