A cross-show, cross-network meeting of DC Universe characters takes place, as Barry Allen (Grant Gustin of The CW's The Flash) travels into National City's dimension to team with Kara Danvers (Melissa Benoist) in the "Worlds Finest" episode of CBS' Supergirl. It's the first crossover involving a CW series character on a CBS program. Both Flash and Supergirl are produced by Warner Bros. Television and DC Entertainment. Their parent company, Warner Bros., owns The CW equally with CBS. Supergirl would move to The CW before the start of its second season.
