In late 2016, Ghost had said a new album was on the horizon for potentially fall 2017, though that was before everything fell apart. Since then, there's been an ongoing lawsuit that eventually resulted in Papa Emeritus outing himself as Tobias Forge, but that doesn't seem to have deterred the band (or Forge) from getting into the studio.
Blabbermouth reports that Forge said in an interview at the German edition of the Metal Hammer Awards on September 15 that Ghost has been in the studio for about a month now, and that he really hopes the new album is coming in April 2018.
"We've been in the studio for about a month now, and by the end of the year, if everything goes according to plan — knock, knock — we're gonna have a new album, not out, but we're gonna have a new recorded and mixed and delivered. And hopefully that means that we're gonna have a new album out by April — possibly, hopefully."
We've heard the new album will be darker and likely about the fall of civilization, so expect some seriously depressing singles to likely start dropping in February or March depending on when in April the album comes out.