In X-Men: Days of Future Past, an all-star cast including James MacAvoy, Michael Fassbender, Patrick Stewart, Ian McKellen reprise their roles to go back in time to stop a homo superior genocide that hasn't happened yet — but will in the near-future. Peter Dinklage also joins up as scientist Bolivar Trask. Got all that? Trust us, original X-Men director Bryan Singer will explain everything. Also, did we mention there's giant killer robots?