The Flash: Who Is Eva McCulloch?

The Flash officially exists in a post-"Crisis on Infinite Earths" world, and that's bringing about some major new developments for the long-running Arrowverse series. Fans got to see exactly what that entailed in Tuesday's midseason premiere episode, which struck a balance between navigating the post-"Crisis" world and expanding upon a season-long mystery. In the process, the series teased a pretty noteworthy character for the episodes that are to come -- and left fans guessing with its cliffhanger ending. Spoilers for this week's episode of The Flash, "Marathon" below! Only look if you want to know!

The episode largely revolved around Iris West-Allen (Candice Patton) and the staff of the Central City Citizen, as they investigated Black Hole, the shadow organization that has seemingly been involved with metahuman trafficking and other shady deeds. Iris met with a man named Gene Huskk, who was believed to have information on the organization through his time spent at McCulloch Technologies. This trail led Iris to McCulloch Industries, and to a meeting with its founder, Joseph Carver. Carver denies any connection to Black Hole, and says that he's running McCulloch in a way to honor his wife, Eva.

Towards the end of the episode, Iris began to question what was going on with Eva, and learned that she had disappeared under mysterious circumstances for quite some time. Iris visited McCulloch Technologies at night and found a mysterious room, which appeared to be Eva's office. Iris began to snoop around -- only to be pulled into a floor-length mirror by a set of hands inside of it.

If that moment is leaving you saying "Wait, what?", Eva's comic counterpart of sorts might help explain things. While we haven't seen Eva (who is set to be played by Efrat Dor) in person yet, it's clear that she's expected to be a gender-bent version of Evan McCulloch. In the comics, Evan is the second man to hold the mantle of Mirror Master, and becomes a frequent and occasionally-terrifying thorn in The Flash's side.

An embittered orphan from Scotland, Evan becomes an assassin and later mercenary for the FBI, who provide him with the gear of the first Mirror Master, Sam Scutter. Evan later grew tired of working with the authorities, and eventually became a member of The Flash's Rogues Gallery.

Eva's arrival on The Flash is literally years in the making, beginning with Sam Scudder (Grey Damon) appearing twice in Season 3. In Sam's first onscreen appearance, Harry Wells (Tom Cavanagh) mentioned that Earth-2's Mirror Master was Evan McCulloch, and used a mirror gun as opposed to superpowers. McCulloch Technologies was then name-dropped multiple times in Season 5, with Nora West-Allen (Jessica Parker Kennedy) seeking out one of the company's mirror guns to fight Cicada.

Now that we've gone deeper inside the world of McCulloch Technologies - and have confronted the supernatural nature of things firsthand - it will be interesting to see where things go next.

The Flash airs Tuesdays at 8/7c on The CW.