The CW has been cranking up the spectacle of its annual Arrowverse crossover event since they started back in 2014, but it'll be hard to top 2019's Crisis on Infinite Earths. Based on the 1985 comic event of the same name, the crossover will span five full episodes and including every DC series featured on the channel. And fans of older DC shows and movies will have something to enjoy, too: Crisis is bringing in many characters and actors from previous DC series like Smallville and Batman: The Animated Series.
The massive crossover was teed up in 2018's Elseworlds event, but it has been referenced throughout multiple Arrowverse series, beginning back in the first season of The Flash five years ago. That's a lot of television to watch, and a lot of history to keep straight. So here's what to know before tuning in to The CW's 2019 Arrowverse crossover Crisis On Infinite Earths.