== Relation to Year Zero ==
Like ''Ghosts I–IV'', the release of ''The Slip'' came as a surprise to most fans, who were expecting the next release to be a
"''Year Zero 2'' ". Trent Reznor has indicated in interviews since the release that a ''[[Year Zero]]'' sequel was still in the works.
It remains unclear what portions, if any, of ''The Slip'' should be considered as canon in the Year Zero storyline. Aside from from [[Art Is Resistance]] logo in the artwork for "Letting You", there are no clear direct references characters or events in Year Zero. Many of tracks do share similar themes, such as abuse of power ("Letting You"), an avatar of destruction ("Demon Seed"), submission to authority ("Head Down"), imprisonment ("Echoplex") and the appearance of entities in the sky ("Lights In The Sky"). Other songs, however, like "1,000,000" and "Discipline", seem completely unrelated and feature more "traditional" NIN themes of personal turmoil. However, through analysis of the lyrics and with consideration of the Year Zero theme. "1,000,000" could be about fleeing from authorities after committing offense in a totalitarian universe. "Discipline" could be a soldier or citizen trying to keep in line and not get caught. The song "Letting You," could be the abusive power saying that they want to use one citizen' s escape so that they can find the rest of the resistance.