Marvel rolls out an epic second trailer for the upcoming blockbuster, X-Men: Days of Future Past. In the clip, we see the ultimate X-Men ensemble fighting a war for the survival of the species across two time periods. The beloved characters from the original X-Men film trilogy join forces with their younger selves from X-Men: First Class, in an epic battle that must change the past — to save our future.

X-Men: Days of Future Past hits theaters May 23rd.