'The Flash' Season 5 Theory: Why Mystery Girl Chose Those "Four Moments"

When we learned the identity of the Mystery Girl in the Season 4 finale of The Flash, we learned that she had made some kind of “huge mistake” by pestering Team Flash at random moments throughout the season.

Spoilers follow for The Flash Season 4.

We found out in the final moments of the season that the Mystery Girl is Nora West-Allen, Iris and Barry’s daughter from 30 years into the future. Shortly after the finale aired on May 22, the show’s executive producer Todd Helbing told Entertainment Weekly, “She comes back for a specific reason.” It was seemingly to supersonic punch the falling satellite in the finale to save Barry’s life, but there was actually way more to it than that.

“There’s four specific times that she came back,” Helbing also said, “and you’re gonna learn about why she chose those four times and how they’re gonna play into not only the mistake that she made, but the consequences for somebody like her, a speedster traveling from the future to the past.” We saw those types of “consequences” in Season 3 with Flashpoint wreaking havoc on the timeline, so what could all this mean for Season 5?

Let’s break down those “four specific times” Nora visited the show and speculate about what each means.

Nora Crashes the Wedding During the “Crisis on Earth-X” Crossover

Just before all the action starts in the “Crisis on Earth-X” crossover event in 2017 — you know, when the Nazis from an alternate reality tried to kill everyone — Nora posed as a caterer at Iris and Barry’s wedding. She walked right up to Barry and said things like “I’m really excited to be here” and “I feel like this will be one for the ages. I’m really happy I got to see it.” Yeah, it was always pretty obvious that this was Barry’s daughter. It’s easy to miss, or even forget, that the very last thing she says to Barry: “Good luck up there. Remember to say ‘I do’.”

Barry totally forgot to say his vows in the original timeline, right? This makes us kind of think that Nora grew up with her mother always telling her stories about her father forgot to say “I do” at his own wedding. It’s possible that this complicated their relationship moving forward and was the starting point of a real wedge between them. Maybe Nora’s first goal going back in time was to try and fix her parents’ relationship?

Nora Pays for Ralph and Cisco’s Coffee

“The Elongated Knight Rises” was a crucial moment in Ralph’s development as a hero, and at the end of the episode, he and Cisco are at CC Jitters getting coffee. But Ralph is broke, and Cisco doesn’t have his wallet. They might’ve been on the brink of some fight or even causing some public scene. That’s when Nora steps in to gleefully pay for them, and she begins ranting about how positive karma is scientifically accurate. Does she somehow know that “paying it forward” here will lead to some beneficial outcome in the future?

She even wore a shirt that said, “You have died of dysentery,” which references the Oregon Trail video game. With that, she was probably trying to impress Cisco. As Ralph and Cisco walk away, cracking jokes with one another, Nora laughs and scribbles those strange symbols in her notebook.

Nora Spills Coffee on Harry and Caitlin

One of Season 4’s absolute best episodes, “Enter Flashtime,” was made even better by this appearance from the “Mystery Girl.” Caitlin and Harry are recapping her growing relationship with her alter ego, Killer Frost. They come to the realization that Killer Frost was genuinely worried about Caitlin’s life. “Interesting …” Harry says, seemingly on the verge of some influential revelation. But then Nora spills a “Killer Frost” coffee frappe drink all over their table. (Is this a thinly veiled but thickly blended heavy-handed metaphor for Killer Frost becoming a supervillain and destroying everything?)

Knowing that later Harry loses his intelligence altogether and Caitlin loses the ability to bring out Killer Frost later in the season, this does seem like it could’ve been a legitimately crucial moment. What if Harry made Caitlin understand something about Killer Frost that changed some part of the future?

In this scene, Nora is her usual bubbly self, talking about the multiple meanings of “jitters” in the Arrowverse and how she’s nervous about meeting people. When Caitlin leaves, wishing her meeting well, Nora’s face turns grave and she says, “It did.” This scene along has spawned tons of theories that the Mystery Girl could be evil, but at the very least, she seems to know something deeply negative about either Caitlin or Harry from the future. Does one of them become a villain at some point in the future?

The more likely explanation here is that Nora knows exactly how dangerous interfering with the past is, and at this point, three changes into her quest, she’s probably starting to worry.

Nora Delivers a Diaper Bag to Joe and Cecille

Nora’s last appearance before the finale confirmed that she was a speedster, and based on her lightning colors, also hinted that she was indeed Iris and Barry’s daughter. In this scene, Nora delivers a diaper bag to Joe and Cecille, saying, “It looks like it’s a gift from someone who wanted you both to know how special you are, someone who understand that time is precious, and right now is all we’ve got.”

Nora has some sentimental attachment to Joe and Cecille, which hopefully means neither of them will die anytime soon. Hopefully, Nora grew up with them as grandparents.

But why would they need yet another diaper bag? And how is it possible that nobody thought to get them one?

Recall that when Barry came out of the Speed Force in the season premiere, he rambled many seemingly senseless things, including, “We’re gonna need more diapers.” This seems a bit too on-the-nose to not be noteworthy, especially because it’s one of the few of those phrases from the premiere that we haven’t gotten an answer on. By the season finale, Cecille and Joe’s baby Jenna West is born, and we can safely assume that Nora is born several years in the future, so who’s having the other baby that triggers someone to say this?

We don’t know a lot about what to expect in Season 5,