The Flash's Grant Gustin has taken to Instagram to share the first image of him and Melissa Benoist as Supergirl on the set of her CBS series. The character of course made a blink and you'll miss it appearance on the Scarlet Speedster's show last night in a scene which appeared to indicate that she lives on another alternate Earth somewhere in the multiverse, but this is our first time seeing them together. Plot details about the crossover are still a secret, but we know that it will happen on Monday, March 28th. Are you excited to see these two meet for the first time? Sound off below!