Supergirl is stunned to discover that a part of Krypton survived. Meanwhile, Alex is attacked while out with Ruby, and Lena considers how far she will go to keep Reign…

Kara makes a major life decision. Meanwhile, J’onn finds out that special DEO-caliber guns have hit the streets of National City.

When multiple children get sick from lead poisoning, Morgan Edge points the finger at Lena and blames her creation of the lead bomb she made to save National City from…

Lena’s ex-boyfriend, Jack Spheer, comes to National City to unveil his big breakthrough in nano-technology, which has the potential to eradicate all diseases. Lena asks Kara to attend Jack’s conference…