Flash & “Supergirl” Crossover Promo Teaser

DC Entertainment has revealed the first promo trailer and new photos from the upcoming “Supergirl” episode which features a crossover with “The Flash”. It’s only brief but the clip teases the episode, titled “World’s Finest,” in which Kara gains a new ally when the lightning-fast superhero (Grant Gustin) appears from an alternate universe and helps Kara battle Silver Banshee and Livewire. The episode is slated to air March 28th.