'The Flash': Could the Mystery Girl Be From Another Earth?

The Flash returns from its month-long hiatus next week, but before the show returns and hopefully sheds some light on one of this season's biggest mysteries there's at least one new fan theory that, if true, could set up The CW superhero series for the recently announced fifth season.

During this year's "Crisis on Earth-X" crossover, fans were introduced to the Mystery Girl, a young woman (played by Jessica Parker Kennedy) who approached Barry Allen (Grant Gustin) right before his wedding. Since that first appearance, fans have had all kinds of theories as to who the young woman is. Theories range from the Mystery Girl being Barry and Iris' (Candice Patton) future daughter Dawn Allen, granddaughter Jenni Ognats, or even a daughter named "Nora Allen" out of reverence for Barry's late mother.

But what if the Mystery Girl isn't any of those people, but is, instead, a version of Barry Allen himself?

A new theory suggests that the Mystery Girl might actually be a gender-swapped version of Barry Allen from Earth-11. In DC Comics, there are 52 separate universes. The same goes for the Arrowverse, and each season we find out a little bit more about the various Earths outside of "our" Earth, Earth-1. This season audiences were introduced to the Nazi world Earth-X as well as a handful of other Earths -- especially when the Council of Wells showed up complete with Earth-13's Wells the Grey and the possibility of an Earth with magic.

In comics, Earth-11 is a world where the largest difference is that genders have been swapped. On Earth-11, Superman is Superwoman, Wonder Woman is Wonder Man, and the earth is more matriarchal. On Earth-11 The Flash would also be female -- a "Carrie" Allen, let's say. Considering that the Mystery Girl appeared during an invasion from Earth-X (the designation for Earth-10), the idea that an Earth-11 hero might hop over to Earth-1 isn't that huge of a stretch, even if her motivation for doing so remains a mystery. However, if Earth-11 were in danger, or even if Earth-11's heroes were villains, it could set up a situation where Barry and Team Flash have to deal with a threat from the multiverse in Season Five.

Admittedly, the Earth-11 theory is a little lighter on explanation than the daughter or granddaughter theories have been, but it's still fun to entertain the idea that the Arrowverse Multiverse is continuing to expand, bringing new and interesting characters with it.

Who do you think the Mystery Girl is? Let us know in the comments!

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