Watch out, Supergirl!

On Monday’s brand new episode of The CW superhero drama, which will markLynda Carter’s debut, things in National City get dicey when the mysterious man inside the pod, Mon-El (Chris Wood), suddenly wakes up from his coma and gives Supergirl a run for her money.

ET exclusively premieres a sneak peek from the episode, where a shirtless Mon-El battles Kara Danvers (Melissa Benoist) inside the walls of the Department of Extra-Normal Operations, aka the D.E.O. -- and his superpowers are unlike anything they’ve seen before.

RELATED: 'Supergirl' Star Melissa Benoist Dishes on the Danver Sisters' Growing Bond

When Kara’s sister, D.E.O. agent Alex (Chyler Leigh), closes in on Mon-El, he skirts arrest and takes off, jumping over the building’s balcony and down to the streets of National City in the dead of night!

Looks like they’re about to have their hands full!

Earlier this summer, ET was on the Vancouver set of Supergirl, where Benoist revealed that the Danver sisters’ bond will continue “to grow” this season.

RELATED: See the First Photo of Lynda Carter From the 'Supergirl' Set

"I think it's the most important relationship on the show," Benoist said. "We are exploring every facet of sisterhood: how women support each other, and how they understand each other. How they communicate, how they love, and how they fight. You are just going to see more and more of that and it's really fulfilling to play those scenes."



Supergirl airs Mondays at 8 p.m. ET/PT on The CW.

For more on season two of Supergirl, watch the video below.