The Flash fans have been waiting patiently to meet Caitlin Snow's (Danielle Panabaker) villainous alter-ego Killer Frost. On Tuesday we'll finally get the honor, when Barry (Grant Gustin), Wells (Tom Cavanagh) and Cisco (Carlos Valdes) visit Earth-2. In that universe, Killer Frost is working with Ronnie's doppelganger Deathstorm (Robbie Amell) on some nefarious missions that sweet scientist Caitlin would definitely not approve of.

Meanwhile, Earth-1 Caitlin will also have her hands full, as she continues her quest to restore Jay's (Teddy Sears) speed by attempting to invent Velocity 9. Check out what Panabaker revealed about Killer Frost, Velocity 9 and more in the interview below:

What was it like getting into the Killer Frost costume, hair and makeup for the first time?
Danielle Panabaker:
It was pretty exciting. Obviously, it's something that we've been talking about and working on for a little while now. To finally get to be on set and duking it out with everyone was such a treat.

What can we expect of Killer Frost and the type of villain she is?
I mean, she's pretty terrible, I'm going to be honest. That's the fun thing about coming to play a villain on our show, you really get to take it far and push the envelope and play and really have a great time. She does not have any good motivation in her.

The Flash to crossover with Supergirl

What aspects of Caitlin might we see in Killer Frost?
I don't know. I haven't really thought about that. I think they're pretty different. I think they're both pretty smart and both pretty loyal, but that's probably as many comparisons I can draw.

Are we going to learn what made Earth-2 Caitlin become Killer Frost?
I think in these couple of episodes, we're just going to focus on Killer Frost as she is now and how she is trying to attack everyone coming from Earth-1.

How does the team react to meeting Killer Frost and Deathstorm?
I think there's a lot of shock, initially. Imagine if you were in that position, seeing two very familiar faces looking extremely different. I think they take time to process it, but they don't have very much time to.

Was it fun to get to work with Robbie Amell again but in such a different capacity?
He's the best and we love having him on the show. It's always such a treat when we can get him.

How will Caitlin react when she eventually finds out about her and Ronnie's Earth-2 dopplegangers?
I think that's something that's maybe kept from Caitlin. I think Barry doesn't want to upset her, so I'm not sure it's information they share with her immediately.

Has Jay known about Killer Frost and been keeping it from Caitlin this entire time?
I imagine if he did, he was doing it to protect her. That would be like finding out your twin is Hitler or something like that. I think if that is something that was kept from her, it was kept with only the best of interests.

The Flash: A quick guide to the DC Universe speedsters

What can you say about Caitlin's mission to invent Velocity 9?
It comes from her deep affection for Jay and she wants to heal him. That really is who she is at the core. She's a doctor. She's a biochemist. Her passion is trying to save people and to take care of them. So when she finds out Jay is sick, she really wants to find a way to heal him and make him feel better.

The name of Jay's doppelganger is obviously a big red flag for fans of the comics. Had you known from the start that he would be Hunter Zolomon or was that also a surprise for you?
I am constantly impressed with our writers and the little tidbits that they share and how smart they are and when they choose to share these things. So it's something that I've been aware of, but hopefully we've been able to keep it a secret from the audience.

How soon will we begin to see the importance of that character and his name resurface?
Soon. You will see it soon.

Killer Frost isn't the only doppelganger we're meeting in this episode. What can you reveal about Earth-2 Cisco, Barry, Joe and Iris?
I think fans are going to be blown away in terms of doppelgangers. It's a testament to how talented our cast is, that they were able to pull off such departures from the characters they play every day.

Will coming face-to-face with their own doppelgangers have lasting affects on the way they any of the characters view themselves?
I do think it affects them. I think it causes them to pause and examine themselves and wonder. But I'll leave the audience to watch the episodes and see how.

How is Caitlin handling the fact that she's been betrayed by Harrison Wells once again?
I think this one's a little different. With Season 1 Harrison Wells, he was pretty black and white. There wasn't a lot of humanity to him that we could find. This Harrison Wells is trying to save his daughter. I think Caitlin can empathize with him a little bit, but it is pretty devastating to find out that he's been lying to them for so long.

Now that Legends of Tomorrow is here, are you itching to play a future or past version of Caitlin?
I would love to. I feel such affection for everyone who is on that show, particularly the ones who started onFlash. I would love to go and play in that world.

Is there anything you can tease about the return of King Shark and the Diggle's trip to Central City?
I'm excited for that episode. Things change for Caitlin and she starts to get in the action a little bit more.

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

(Full Disclosure: is owned by CBS, one of The CW's parent companies.)