One More CW DC Crossover Trailer

The CW has released one more trailer for its Heroes v Aliens event, a four-night crossover of its DC Comics-inspired shows that kicks off with next week’s “Supergirl” and continues with “Arrow,” “The Flash” and “Legends of Tomorrow”.

This one has a bit more about the alien menace, shows some key scenes from “The Flash” episode in particular, and explains a bit more about how Supergirl figures into the action. It all kicks off on Monday.