The X-Men's day of reckoning is upon them in the first trailer for director Bryan Singer's "X-Men: Apocalypse," as En Sabah Nur -- the eponymous Apocalypse -- reawakens.

Professor X (James McAvoy) and Mystique (Jennifer Lawrence) must face the mutants' greatest threat yet, but they aren't alone: Newcomers like Scott Summers (Tye Sheridan), Jean Grey (Sophie Turner), Nightcrawler (Kodi Smit-McPhee) and Storm (Alexandra Shipp) join them in their fight for all mutantkind -- even if it means going up against old friends like Magneto (Michael Fassbender).

Also starring Oscar Isaac, Nicholas Hoult, Olivia Munn, Lucas Till, Evan Peters, Josh Helman, Lana Condor and Ben Hardy, "X-Men: Apocalypse" opens May 27, 2016.