The CW’s big superhero crossover event has begun. Starting with Supergirl on Monday, then leading into The Flash, Arrow and Legends of Tomorrow the rest of the week, all four shows in the network’s Arrowverse will finally come together with its heroes facing a race of aliens known as the Dominators. While Supergirl’s Earth has its fair share of aliens already, the action actually kicks off on The Flash, when Barry Allen (Grant Gustin) is forced to seek out Kara Danvers (Melissa Benoist) and ask for her help.

The crossover story itself is loosely based on the 1980s comic book miniseries Invasion, and it was actually quite an undertaking for the cast and crew to bring to life. It’s taken six months of planning to take the story from script to screen, not to mention the work on “cutting-edge prosthetics and computer effects” that executive producer Marc Guggenheim says were used for …

Click to continue reading Arrowverse Crossover Video Goes Behind the Scenes of Invasion!