Supergirl returns to the small screen for a second season, and it's coming to a different network. Now airing on The CW, Supergirl will become part of the DC superhero lineup of shows along with The Flash, Arrow, and Legends of Tomorrow. The first season set up who the character is along with her supporting cast and new villains to fight. There was even a cliffhanger in the Season 1 finale, which will definitely be addressed in the Season 2 premiere.

　　Despite the show moving to a new network, there will still be some familiar elements. In case you missed the first season or need a refresher on what happened, here's everything you need to know. There will be spoilers for Supergirl Season 1 below.

　　Supergirl's Sister and the DEO

　　Like Superman, Kara Zor-El was sent to Earth before Krypton exploded. The difference is, the planet's destruction sent her ship into the Phantom Zone for 24 years. When she arrived on Earth, Superman placed his cousin in the care of the Danvers. Kara grew up keeping her powers a secret until her older adopted sister, Alex, was on a plane about to crash. Saving the plane, Kara's abilities were revealed to the world.

　　Kara soon discovered her sister was actually working for the Department of Extra-Normal Operations (DEO). Supergirl worked with her sister in dealing with other alien threats on Earth.

　　Hank Henshaw and Martian Manhunter

　　The DEO was under the leadership of Hank Henshaw. Hank was skeptical of Supergirl's lack of experience and put her through a rigorous training regimen. Alex and Kara discovered that Hank was on the same mission where Alex's father, Jeremiah, was killed and suspect Henshaw was responsible. It turns out Henshaw was the alien refugee, Martian Manhunter, whom the original Henshaw was determined to kill. Jeremiah fought Henshaw to save the alien, which resulted in their deaths. Martian Manhunter, a shape-shifter, took Henshaw's form to avenge Jeremiah's death and to ensure aliens were treated humanely by the DEO. Martian Manhunter's identity was exposed, and he eventually accepted as a hero.

　　Cat Grant

　　Cat Grant, a former reporter at the Daily Planet in Metropolis, built her own media empire in National City. Supergirl, in her civilian guise, worked as the assistant to the cold and ruthless media queen. As hard as Cat was on Kara, she ended up being Supergirl's biggest supporter and even coined her superhero name. Kara and Cat had their ups and down during the season, but Kara is given a promotion at the end.

　　James Olsen

　　James Olsen moved from Metropolis to National City to become the art director for CatCo. It turns out he's aware of Kara's abilities, and Superman sent him to National City to keep an eye on her. Kara is immediately smitten with Olsen despite him being in a shaky relationship with Lucy Lane. Lucy realizes James and Kara share an attraction to each other and ends the relationship. James and Kara are now able to explore their feelings towards each other.

　　Enemies

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　　Supergirl's involvement with the DEO and as National City's protector put her up against many threats. A hacker in National City turns out to be Indigo, an alien determined to destroy National City. Astra, Kara's mother's twin sister, was imprisoned in the Phantom Zone and led an army against Supergirl and the city. Non, another Kryptonian imprisoned in the Phantom Zone and Astra's husband, continued the fight after Astra was killed.

　　Livewire was a former CatCo employee fired by Cat Grant. An electrical accident gave her powers which she used to try to get revenge. Silver Banshee was another of Cat's assistant who was fired. She finds out the women in her family are cursed by the spirit of a banshee and can only be quieted once revenge is achieved. Red Tornado was an android created by T.O. Morrow for the government. When Supergirl overpowered the android, General Sam Lane fired Morrow. Morrow sends the android after Lane.

　　Maxwell Lord publicly proclaimed Supergirl as an alien threat. He constantly worked on ways to defeat her and even discovered her true identity. Despite his reluctance, Lord eventually forms an uneasy alliance with Supergirl and her sister.

　　Superman?

　　Superman's presence was barely felt during the first season. This was explained by his desire to allow Kara to grow as a hero, on her own. When Supergirl was nearly defeated by Reactron, James called in her cousin. This angered Kara, and Superman tells her he believes she is capable of handling everything on her own. He later has a brief cameo when Non unleashes the Myriad effect, which puts everyone under its control except for Supergirl, Cat, and Max Lord.

　　In the second season, Superman will have a bigger presence. He'll appear and fight alongside Kara against a new emerging threat.

　　Flash Crossover

　　The Flash appears from an alternate universe. He teams up with Supergirl against the combined threat of Livewire and Silver Banshee.

　　With Supergirl moving to The CW, it's been announced the show will be part of the big crossover between The Flash, Arrow, and Legends of Tomorrow.

　　Ship at End/Cliffhanger

　　After Supergirl deals with the threat of Myriad, Martian Manhunter/Hank Henshaw is reinstated into the DEO and Kara gets a promotion at CatCo. Supergirl and her confidants celebrate at her apartment when a pod similar to the one she arrived in crashes outside National City. She and Martian Manhunter fly to it to investigate. When she opens the pod, she lets out a gasp.

　　Supergirl Season 2 premieres on Monday, October 10, at 8 PM EST/PST.