Supergirl: Everything You Need to Know About Season 2

Last season, The Flash and Supergirl had a crossover episode, and with them on the same network now, it'll be even easier to facilitate. It'll also be much, much bigger: at this year's Upfronts event, the CW president announced a four-way crossover event for their DC shows, meaning it'll be The Flash, Supergirl, Arrow, and DC's Legends of Tomorrow. Look for the huger-than-huge mashup in December.