Supergirl/Flash Crossover “World’s Finest” Promo

It’s finally here! Barry Allen has ended up in the universe of Supergirl. Now, as Kara works on helping her new friend home, both the Silver Banshee and Livewire decide to shake things up. It’s a race against time and evil in Supergirl, season 1, episode 18 promo: World’s Finest.