Last week's episode of CBS's "Supergirl" saw Kara tap into her anger in a way she never had before, unleashing the full intensity of her heat vision upon the android menace named Red Tornado. The act destroyed her foe, but it also had consequences -- in the wake of using her abilities in such a fashion, she found herself powerless.

During a visit to National City -- aka, the "Supergirl" set -- Executive Producer Andrew Kreisberg explained what happened to the press, including CBR News. "It's from the comics," he said. "It was a Geoff Johns idea, which was that Superman or any Kryptonian's cells are basically suffused with solar radiation, and that's where they get their powers from. The heat vision is an expulsion of that energy. That's where it comes from. You could actually run out, and you would need to recharge. I was such a fan of that comic and that run, and talked to Geoff and said, 'Could we do something with that?' And he was like, 'Absolutely.'

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"She's in this place where she's struggling with her role and [asking] 'Am I doing this well?' and 'How should I be doing things?' and 'How should I go about things?'" Kreisberg continued. "Then, we take it away from her and let her really appreciate what it means. We also just love the idea of, like Oliver [Queen] and like Barry [Allen], that Kara's a hero whether she has her powers or not. There's this great moment in that comic book where Superman confronts a guy with a gun and basically talks him out of it even though he knows if the guy pulls the trigger, he'll get killed. That became the centerpiece of that episode, and you saw that a little bit in the trailer. But she basically emptied her powers killing the Red Tornado, and she needs a couple of days. Unfortunately, it was the day of the giant earthquake."

Supergirl herself, Melissa Benoist, had her own take on the different side of Kara we saw fighting and destroying Red Tornado. "Everything was building to that," she said. "Her life has really been tossed upside down since she's come out with her powers and she's really had to grapple... with her past, what these powers mean on Earth, what being Supergirl means, and what kind of hero she wants to be. I think anyone would be overwhelmed with that, especially someone who didn't allow herself to be her true self for such a long time."

Ultimately, "Human for a Day" is about Kara struggling with her identity in the face of losing her powers. "Obviously, it's a frustrating feeling, but I think the whole point of the next episode is, how does one -- you don't need powers to be a hero, and what is in Kara's heart is what makes her a hero. So, how does she deal with this tragedy in the city, and how does she save people without being able to fly and have super strength and be made of steel? How does she handle that?"

"Supergirl" airs on Mondays at 8:00pm on CBS; "Human for a Day" airs Dec. 7