With a May 2016 release date already on the books, the folks behind "X-Men: Apocalypse," like director Bryan Singer, are already hard at work on the next mutant adventure.

And as if we needed some teasing evidence that the work is being done, Singer shared this photo of the "Apocalypse" script treatment with his Instagram followers.

Thanks to Singer's infuriating, purposeful framing of the picture, there's nothing too revealing, aside from the fact that the Four Horsemen, who were teased in the "Days of Future Past" post-credits sequence, are a part of "Apocalypse."

The Four Horsemen of Apocalypse are a group of mutants, typically brainwashed and with enhanced powers, that do the villain's bidding.

"X-Men: Apocalypse" opens in theaters on May 27, 2016.