Watch Supergirl – Season 1 Episode 18: Worlds Finest
Cast: Katie McGrath , Melissa Benoist , Chyler Leigh , David Harewood , Jesse Rath , Nicole Maines , Azie Tesfai , Julie Gonzalo , Staz Nair , Peta Sergeant
Directors: Greg Berlanti , Andrew Kreisberg , Ali Adler
Watch Supergirl – S1E18
Episode Overview
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.
