'Supergirl' Cast Tease What's Next For Samantha

Supergirl took a big step towards its newest Big Bad in this week's episode, and the cast is excited to show fans what's to come.

Spoilers for tonight's episode of Supergirl, 'Wake Up', below.

Tonight's episode saw Samantha (Odette Annable) beginning to realize the truths about her extraterrestrial origin. With a confrontation between her and Kara Danvers/Supergirl (Melissa Benoist) on the horizon, Benoist says that fans will be intrigued by how it culminates.

"I think Reign is going to surprise people." Benoist said during a recent set visit. "She is pretty spectacular to behold and she definitely has given Supergirl-- she will give Supergirl the fight of her life. I think what sets her aside from the villains that we've seen-- the big bads that we've seen up to this point on the show, she has a really surprising backstory that's quite grounded, that gets you really invested in who she really is fundamentally."

Kara and Samantha have previously had a friendly rapport, largely thanks to their shared connection to Lena Luthor (Katie McGrath). And according to McGrath, this revelation could change the trio in pretty complex ways.

"I can't imagine that it isn't going to become difficult with Sam essentially being Supergirl's arch-enemy and all three of us being friends." McGrath explained. "It's got to come to a head somehow. But how and when? I'm not quite show. You'll just have to watch all the episodes."

And when it comes to another one of Samantha's cohorts, Alex Danvers (Chyler Leigh), the impact of that reveal won't necessarily be shown yet.

"As far as I know from Alex's perspective, she wouldn't put the two together." Leigh revealed. "But, again, Alex isn't in CatCo … She hasn't come across that or put those two together, which is kind of funny because she probably should."

Supergirl airs Monday nights at 8/7c on The CW.