If you're like many fans, you've watched the trailer and clips for Avengers: Age of Ultron about 3,000 times by now, analyzing every single frame for all its worth. If so, you may have noticed a mysterious woman show up a few times who isn't part of the Avengers. We now know a bit more about who this might be.

You'll notice the mystery woman in this clip released by Marvel earlier this week. In this scene, all the major characters are together at the Avengers tower, but then there's one woman on the far right who we've never seen before. She appears 51 seconds in to the clip.

She can also be seen in the official trailer, standing next to Thor 37 seconds in.

Of course the Internet went wild all week with speculation about who this might be. Some speculated it was Maria Hill, others thought it could be Jane Foster (Natalie Portman), while still others speculated it could be Captain Marvel. But Yahoo has confirmed this as South Korean actress Claudia Kim, aka Kim Soo-hyun.

Slashfilm reported on her addition to the cast earlier this year, and she can be seen here on the set with Joss Whedon.

Image via Twitter from Claudia Kim

There's still room for speculation though, as Marvel would not reveal the character she's playing. However, they did confirm that she will be playing a "substantial supporting role," according to Slashfilm.

The actress said earlier this year she'd be playing “a doctor/scientist who is friends with Tony Stark," according to Slashfilm, and so the current theory is that she is playing Suzi Endo, a researcher from Stark Industries. It's entirely possible though that she'll be playing a completely new character not from the comics at all.

Either way, we have six months to go until the premiere of Age of Ultron, so speculate away!