'Supergirl' Season 3 Episode 1 Air Date, Synopsis, Spoilers: There Is A Mysterious New Threat To National City

There are only two more weeks before "Supergirl" Season 3 premieres on The CW. The network has already released the synopsis of Episode 1 titled "Girl of Steel" and it gives viewers a peek into Kara Danvers' (Melissa Benoist) life after Mon-El (Chris Wood). 

Last season, in a desperate decision, Kara launched Mon-El into outer space to save him as the Earth purges the Daxamites. The Prince of Daxam's spaceship unexpectedly entered a wormhole that suddenly appeared in front of him and is not expected to reappear anytime soon. 

As expected, Mon-El's absence is going to play an important role in "Supergirl" Season 3. The premiere episode will see Kara work doubly hard as a superhero to forget her grief.

"Kara deals with the loss of Mon-El by focusing all her energy on being Supergirl and the mysterious new threat against National City," the synopsis for "Girl of Steel" read (via Carter Matt). "Alex (Chyler Leigh) confessed a secret to Maggie (Floriana Lima) about their impending nuptials. A citizen of National City has a mysterious connection to Kara and Lena (Katie McGrath) makes a bold move."

Because the world does not stop turning just because she has her heart broken, Kara will instead focus all of her energies to her duty as the superhero of National City. Good thing that she has Lena looking out for her because, apparently, the citizen who is somehow to Kara is likely Samantha (Odette Annable). The new character will eventually become Reign, the big bad of the upcoming season. 

In DC Comics (via Deadline), Reign is a blood-thirsty, powerful, one of the five "World Killers" created by Zor-El himself. She and the other monsters survived the destruction of Krypton and eventually arrive at Earth to battle Supergirl. 

"Supergirl" Season 3 Episode 1 ("Girl of Steel") will air on Oct, 9 on The CW. Watch the trailer below.