"It will address historical mutant-cy," Singer told EW, "meaning the deep past, mutant origins and things like that. It’s something that’s always intrigued me when we think about our Gods and our history and miracles and powers.”
In terms of specific plot, the director is saying nothing, but does confirm that "something that happens in Days Of Future Past causes what's going to happen in Apocalypse". He says he's as-yet undecided about whether there will be an Apocalypse teaser during the credits of this year's movie. Given recent precedent, however, we wouldn't call it unlikely.
And will Singer actually direct Apocalypse? That too is still to be determined. "I’m co-writing the story and I’m producing it,” he says, "and I’m negotiating to direct. We’re in the process. We’re trying to figure it out, schedules. My desire would be to direct it.”
For more Apocalyptic speculation, head over to Empire's handy first-thoughts guide. Days Of Future Past, meanwhile, stars Michael Fassbender, James McAvoy, Jennifer Lawrence, Peter Dinklage, Nicholas Hoult, Evan Peters, Patrick Stewart, Ian McKellen, Hugh Jackman, Ellen Page, Shawn Ashmore, Fan Bingbing, Daniel Cudmore... the list goes on.