Overview:

"Crisis on Infinite Earths" is the sixth Arrowverse crossover event. "Crisis on Infinite Earths", inspired by the comic of the same name, continues plotlines established in the previous crossover, "Elseworlds". The preceding episodes of Arrow season eight and much of The Flash season six serve as a prelude to the crossover. In "Crisis", the Monitor gathers Green Arrow, the Flash, Supergirl, Batwoman, Sara Lance, Ray Palmer, and several others from throughout the multiverse to stop the Anti-Monitor from destroying reality. The crossover's events result in some aspects of the Arrowverse being rebooted, affecting all of the series.