'The Flash's Grant Gustin Has Known Mystery Girl's Identity Longer Than Anyone Else

We know that Carlos Valdes knows just who Mystery Girl is on The Flash, and it turns out, Grant Gustin does too.

However, Grant has known for much longer than anyone else – since before the season even started!

In a new interview with EW, Grant opens up about the mysterious character, played by Jessica Parker Kennedy, who first pops up at Barry and Iris’ wedding.

“I’ve known since before we started this season,” Grant shared. “It’s been the thing that I’ve been most excited about all season, which sounds ridiculous because it’s really a season 5 thing. I’ve spent all of season 4 being excited about this thing that we’re going to do in season 5!”

He adds that it will “be one of the cooler reveals that we’ve done in a couple seasons” and that he does know “who she is and a little bit about her backstory, and how she’s connected to a handful of characters.”

Okay, Grant. You can spill the secrets now!

“You get the question answered as to who she is,” executive producer Todd Helbing also explains. “There’s actually an extra little bonus where something happens where you’ll realize exactly how she’ll play a part in the future.”

TELL JJJ: You have any more ideas on who Mystery Girl is?