It has finally happened!! After a huge outcry from fans, the Flash will crossover with Supergirl. CBS announced that the Scarlet Speedster will give Supergirl a hand later this year which will undoubtedly please fans of both shows. This crossover is possible since the DCTV universe shows share executive producers. Fans have been clamoring for Supergirl to cross into the Flash/Arrow universe ever since the series was first announced. While details of Barry Allen’s visit to National City have yet to be revealed, the episode is scheduled to air Monday, March 28!