We've just barely left the Arrowverse Elseworlds crossover behind, but we've already got our minds turned toward 2019's crossover, known as Crisis on Infinite Earths.Beyond the title, which was revealed at the end of the Elseworlds crossover, we know next to nothing about Crisis on Infinite Earths. Speculation abounds about what storylines will be included (and how closely it will follow the comics), but TV Guide can reveal one key element from [...]