Superhero secret identities are as much a part of a good character's makeup as their superpowers, and Supergirl star Katie McGrath thinks Kara Danvers' civilian persona actually adds something unexpected to the Girl of Steel: the chance to be vulnerable. McGrath recently voiced her thoughts on Supergirl and the character's mild-mannered alter ego while also addressing concerns over whether or not Lena Luthor should have figured out by now that her close friend Kara is actually National City's Kryptonian protector. As she puts it, there's a very good reason why the member of the Luthor family is still seeing double and why it's so important for the show and the character that the Kara Danvers persona continue to be there for Kara Zor-El.

The comments came during a recent Supergirl set visit attended by Screen Rant, where McGrath discussed Lena's role in the ongoing third season of The CW show, and addressed just how many times she's been asked whether or not her character is secretly wise to Kara's thinly-veiled deception. As it turns out, McGrath is a firm believer in Supergirl's secret identity and suggests those who find her disguise to be on the dubious side use the same suspension of disbelief that allows them to enjoy a show about a flying alien woman with heat vision.

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When asked about Lena's knowledge of Kara's secret, McGrath said:

"No. It`s just like flat-out no. I get asked this a lot and my answer is still the same. There're a couple of things: If you can believe that there's a show about aliens and a girl who can fly, then you believe that I don't know they're the same person. You just have to accept. And then, also, if everybody knows her secret then she has to be Supergirl all the time, and the great part of the show is the fact that she's both, you know? She can be vulnerable with me and human with me; she doesn't always have to be the hero. And for a story, that I think is the most compelling thing to watch. You see somebody be vulnerable. And because she doesn't have to be Supergirl all of the time, you can see her as a vulnerable character."

Just accepting Lena doesn't know Kara and Supergirl are one in the same seems like a fairly easy and reasonable request from someone who ought to know a thing or two about what's going on in Lena Luthor's head. But the second half of McGrath's statement actually makes for a compelling reason as to why it's important for the character to be able to switch between Kara Danvers and Supergirl: It allows to be more human, giving Kara and Supergirl a chance to show another side to herself and put aside the 'S' shield for just a moment to experience the world as someone without god-like powers would.

No doubt there will always be fans skeptical that a pair of glasses and a ponytail are enough to keep the world from discovering Supergirl's secret, but McGrath's not wrong when she urges viewers to consider the type of program they're watching before scoffing too hard. After all, if you're willing to believe a girl can fly, believing in the efficacy of a bargain-basement disguise should be a snap.

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Supergirl continues next Monday with 'Wake Up' @8pm on The CW.