On Episode 7 of CBS's "Supergirl," which airs on Dec. 7, an earthquake hits National City, and just when the citizens need Supergirl the most, she loses her powers.

In a preview for the upcoming episode, titled "Human For A Day," Kara (Melissa Benoist) tells James (Mehcad Brooks) that she has no powers because she wore them out. To make matters worse for the hero, an earthquake hits the city and puts everyone at risk.

According to TV.com, because of the earthquake, Kara's sister Alex (Chyler Leigh) and her boss Hank (David Harewood) find themselves trapped inside one of the DEA's bases together with one of the escaped prisoners from Fort Rozz named Jemm (Charles Halford).

With her sister in danger, Kara is determined to help save the day, even as a human.

However, without her powers, that proves to be a challenge and even puts her own life in danger. The hero will have to search within to figure out how to get her powers back and once again become the hero she is supposed to be.

The episode won't only feature destruction and chaos. James, Winn (Jeremy Jordan) and Cat (Calista Flockhart) will also have to face personal struggles after the earthquake affects their jobs and families.

The series recently received great news, when a recent CBS press release announced that the show will be getting a full season order and will have a total of 20 episodes.

Speculation about the series making a crossover with CW's "The Flash" increased with the announcement of the full season order, but executive producer Andrew Kreisberg put those rumors to rest, according to The Hollywood Reporter.

"We don't even know if we could, legally. And quite frankly, just making the 'Arrow-verse' which is what we call 'Legends,' 'Flash' and 'Arrow' work and then making 'Supergirl' work, it's enough of a challenge without having to add a fourth player," he said.

Check out the Episode 7 preview below.