World's Finest: 'Supergirl' and 'The Flash' Crossover Details and Poster Released

CBS has released the synopsis for the much anticipated crossover event between 'Supergirl' and 'The Flash' entitled World's Finest. The adorably photogenic  Melissa Benoist and Grant Gustin share a promotional poster to determine "Who is the fastest person alive?" A rift on the iconic 1967 cover of Superman #199 where Superman raced The Flash to a draw. 

The plot of World's Finest pits Kara and Barry against Silver Banshee and Livewire. Here's the official description. 

Kara gains a new ally when the lightning-fast superhero The Flash (Grant Gustin) 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.

 “Worlds Finest” airs on CBS March 28th at 8 p.m.