Year Zero (also known as Halo 24) is the fifth studio album from American industrial rock band Nine Inch Nails. The album was produced by Nine Inch Nails frontman Trent Reznor and Atticus Ross, mixed by long-time collaborator Alan Moulder, and mastered by Brian Gardner. Year Zero is a concept album criticizing the United States government's policies as of 2007 and projecting a dystopian vision of its impact on the state of events in 2022. Reznor indicated that this required a completely different approach from his usual style of lyric writing. Reznor also stated that the album ws "part of a bigger picture of a number of things [he was] working on".

The Year Zero concept has included a remix album, an alternate reality game, and a potential television or film project. The alternate reality game attached to the album expanded upon the fictional storyline of the album through other media including various websites, pre-recorded phone messages, and murals. The campaign was organized by Reznor himself and 42 Entertainment, notable for a number of other alternate reality games and viral marketing campaigns. Much of the ARG revolved around a number of Nine Inch Nails live performances during the Performance 2007 tour. During these performances a number of high-quality audio files from the then-unreleased album were intentionally leaked to the public.

The album received generally favorable reviews, many of which were also favorable towards the ARG. The album spawned two singles, "Survivalism" and "Capital G", though the latter was only released as a promotional single.