July 29, 2016: Supergirl to Crossover With All Three DC/CW Shows

“DC’s Legends of Tomorrow” Producer Marc Guggenheim revealed during San Diego Comic-Con last week that not only will The CW’s four DC Comics-based TV shows crossover in a mega-event, but Supergirl will be central to the plot.

Stopping short of calling it a full-on Supergirl crossover, Guggenheim confirmed the Girl of Steel will be stopping by all three of CW’s other DC shows. “It’s an external threat from outside the shows that will involve Supergirl coming over to “The Flash,” then “Arrow” then “Legends of Tomorrow.” What that threat might be, Guggenheim did not disclose.

Source: ComicBookResources.com