Last year, The CW attempted an ambitious endeavor with its slate of superhero shows: A crossover story that played out over the course of that week’s episodes. It was a resounding success, and a lot of viewers (including us) thought the story was better than what we’ve seen in the Justice League movies. Since it worked so well last season, the network is doing it again, with another story that brings together Supergirl, The Flash, Legends of Tomorrow, and Arrow. While the crossover episodes may be great fun for viewers, they’re a logistical nightmare for producers. Each of the four shows is already on a demanding schedule, and The Flash star Grant Gustin told us things get even crazier when the crossover episodes are filmed. (Click on the media bar below to hear Grant Gustin)
The second half of this season’s CW crossover event airs tonight, with The Flash airing Part 3 at 8/7c, followed by Part 4 on DC’s The Legends of Tomorrow at 9/8c.