Details: Aired in 2017. This is a four-part crossover, television show special comprised of episode 8 of season 3 of Supergirl, episode 8 of season 6 of Arrow, episode 8 of season 4 of The Flash, and episode 8 of season 3 of Legends of Tomorrow, in that order. Each episode is about an hour-long and aired on the CW.
Ever since the CW started airing more than one DC Comics superhero show, they began to air an annual crossover episode where the heroes on all their respective superhero shows team up in a self-contained story arc and fight a common enemy. This means more special effects, more action, and more funny/strange moments between characters who would normally never interact with one another.
The crossover miniseries this year is the largest to date as it combines the cast of Supergirl, Arrow, The Flash, and Legends of Tomorrow. You’d think it wouldn’t work, but despite some cringe-y moments, it mostly does. If you are at all a fan of the CW’s superhero shows, this is the television event you should watch.