Twenty-four-year-old Kara Zor-El, cousin of Superman, who was taken in by the Danvers family when she was 12 after being sent away from Krypton, must learn to embrace her powers after previously hiding them.

Kara must put doubts aside as she tries to apprehend an escapee from the Kryptonian prison; Cat pressures James for an interview with Supergirl.

Supergirl's powers are put to the test when one of Superman's most formidable enemies, Reactron, shows up in National City to take her down. In the meantime, Cat makes plans to run an expose on Supergirl.

Kara must protect National City from a series of bombings and babysit Cat's son, while James is visited by Lucy Lane.

Kara's foster mother visits for Thanksgiving, while an accident transforms a volatile CatCo employee into Livewire.

Stress makes Kara go too far during a training exercise against a military cyborg commissioned by General Sam Lane, while Cat's mother comes to visit and Winn helps Alex investigate her father's death.

Supergirl, with her recently drained powers taking too long to return, must deal with life without them, while DEO has a powerful escaped alien prisoner in their headquarters.

Supergirl fights against her aunt and learns some heartbreaking news about her mom, while Catco is dealing with a hacker.

A standoff ensues between the DEO and Astra's forces also Non kidnaps Hank, while Kara tries to refute Cat's allegations that she's Supergirl.

Kara helps Hank face his painful past when a White Martian, who wiped out all of the Green Martians from Mars, kidnaps Senator Miranda Crane who is an anti-alien politician. Adam Foster who is Cat's estranged son arrives in National City.

Kara must deal with a twisted version of Supergirl, while venturing into a possible romance.

A parasitic alien attaches itself to Kara and traps her in a world where Krypton was never destroyed, leaving Alex, Hank and the DEO to fend off a Kryptonian attack without her.

Kara battles the Master Jailer while dealing with a second assistant at CatCo and disagreeing with James over the DEO's methods.

Kara travels to the Fortress of Solitude hoping to find information on how to defeat Indigo, a being from her past who can travel through the Internet. In the meantime, James and Lucy reach a crossroads in their relationship.

Red Kryptonite makes Kara malicious and dangerous while Cat appears on The Talk (2010) to discuss Supergirl.

J'onn J'onzz reveals how he met Jeremiah Danvers and assumed the identity of Hank Henshaw.

Kara gains a new ally when the Flash arrives from a parallel universe and helps her fight the Silver Banshee and Livewire in exchange for helping him return home.

Non and Indigo use mind control to make the citizens of National City their army, so Kara must find a way to save her friends.

Supergirl is forced to do battle with an unexpected enemy as she risks everything - including her life - to stop Non and Indigo from destroying everyone on Earth.