Ep 18. Shelter from the Storm

Kara and the DEO team up with Samantha to try and find a way to defeat Reign. Samantha's powers continue to grow, making her unstable, and the team realizes that they need to find a way to remove the dark Kryptonian energy from her body before it's too late. Meanwhile, Mon-El returns to Earth with shocking news about their future, and J'onn struggles with the decision to reveal a secret to his father. In the midst of it all, a group of children become the targets of a villainous plot, and Supergirl and her team must rush to their rescue. As the battle against Reign intensifies, Kara will have to make some tough choices in order to keep the people she loves safe.