According to Stephen Amell, the 2017 crossover between Arrow, The Flash, Supergirl, and Legends of Tomorrow - now officially titled "Crisis on Earth-X" - will not only be the Arrowverse's biggest crossover yet, it will also feel like a "four-hour movie."
In December 2014, The CW aired a two-episode crossover between The Flash and Arrow that thereafter became an annual event. The following year, the crossover increased in scale and introduced new characters such as Hawkman, Hawkgirl, and Vandal Savage in an effort to set up Legends of Tomorrow. In 2016, the crossover grew to include Legends of Tomorrow and also incorporated characters from Supergirl, as the heroes worked together to fight off an alien invasion. This year, "Crisis on Earth-X" will take the crossover to a whole new level by encompassing all four shows in a two-night event.
During a panel at Salt Lake Comic-Con, Arrow star Stephen Amell discussed "Crisis on Earth-X" and compared it to previous crossovers:
When we first did the crossover, I guess back in our third season and The Flash’s first season, it was very much like ‘It’s an episode of The Flash where I show up, and then an episode of Arrow where he shows up. And even last year, it was like ‘You know, Flash showed up on Supergirl, and then it was an episode of The Flash, an episode of Arrow, and an episode of Legends.’ But this year is just a four-hour movie.
Amell added that each episode feels like part of the crossover, rather than just an episode of Supergirl, The Flash, Arrow or Legends of Tomorrow. He also promised that the crossover is going to be "really, really good."
Though showrunner Marc Guggenheim has admitted that the epic scale of "Invasion!" will be hard to top, "Crisis on Earth-X" will attempt to do just that by pitting the casts of all four shows against villains from an alternate universe called Earth-X. The event will take place during the much-anticipated wedding of Barry Allen and Iris West. The crossover will also feature The Ray, played by Quantico's Russell Tovey, who will later star in the animated series, Freedom Fighters: The Ray on the digital streaming service, CW Seed.
"Crisis on Earth X" takes place across two nights on Monday, November 27 and Tuesday, November 28 on The CW. Supergirl and Arrow will air on Monday and The Flash and Legends of Tomorrow will air on Tuesday.
Source: Stephen Amell [via Comic Book]