SCP-5000 is an entry written by the author Tanhony for the SCP Foundation, a collaborative fiction wiki where anyone may post and collectively edit articles. In the fiction it takes the form of a mechanical device built by the Foundation, the "Absolute Exclusion Harness," classified as Safe and now mostly defunct, retaining only the ability to store files. The records left inside that harness make up the body of the story.
The article's title is a single word: "Why?" Pietro Wilson, a Foundation employee, dons the harness and escapes alone from a site where his colleagues are being slaughtered, and soon learns that the Foundation has resolved to exterminate all of humanity. It releases SCP-682, circulates the face of SCP-096 across social media, and otherwise unleashes upon the world the very threats it once contained. Yet the reason the Foundation turned against humanity is never disclosed. True to its title, the question "Why?" is left sealed without an answer, and that absence is the heart of the work.
SCP-5000 won first place in the SCP-5000 Contest, whose theme was "Mystery." It was praised for inverting the Foundation — long humanity's protector — into humanity's antagonist, and for rendering an enormous catastrophe through the narrow perspective of a single survivor. Because it deliberately withholds every answer and invites readers to assemble the clues themselves, it is regarded as one of the most discussed articles in the history of the SCP wiki.