The black envelope cautions: “Actions have consequences.”

Nine Inch Nails dropped their surprise EP Not the Actual Events in December, with the band pre-warning fans that digital copies would be accompanied by an unknown “physical component.”

As Pitchfork points out, those packages have now arrived and they come covered in a messy black powder. The black envelope contains warnings like “this will leave a mess” and “actions have consequences,” while also housing various texts and photos.

Intriguing mail today… It's gonna leave a mark. Thanks

— Seb Courvoisier (@LePhasme) February 28, 2017

Thank you

— Jordan Currier (@jkcurrier) March 2, 2017

Got my

— KnowKontrol (@knowkontrol) March 1, 2017

Just got the most mysterious package from Nine Inch Nails!! WTF!?

— Codie Conklin (@ladycroft214) March 1, 2017

— Lydia Munster (@LydiaMunster) March 1, 2017

Frontman Trent Reznor has previously described the EP as “an unfriendly, fairly impenetrable record that we needed to make.” In December, he also revealed that he plans to release “two new major” NIN projects this year.