Here it is, the third official trailer for X-Men: Days of Future Past! Pure amazement!
Synopsis:
Bonded by war. United by hope. See the X-Men face their greatest challenge together in X-Men: Days of Future Past.
The ultimate X-Men ensemble fights a war for the survival of the species across two time periods in X-MEN: DAYS OF FUTURE PAST. 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.
Source: X-Men Movie, 20th Century Fox