Today we have the 3rd new promo for the upcoming 18th episode of ‘Supergirl‘ titled, ‘World’s Finest‘. This is the very highly anticipated crossover between ‘The Flash‘ and ‘Supergirl‘. In this promo we see a new device added to the chest of Barry’s suit. We will let you guess exactly what the function of that is. Check out the promo below and share your thoughts AFTER THE JUMP!
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.