Kara turns on her friends and the citizens of National City after being exposed to Red Kryptonite makes her malicious and dangerous. Also, Cat appears on THE TALK to discuss Supergirl.

Kara gains a new ally when the lightning-fast superhero The Flash suddenly appears from an alternate universe and helps Kara battle Siobhan, aka Silver Banshee, and Livewire in exchange for her help in finding a way to return him home.