From Unofficial Handbook of the Virtue Universe
The "Nightshift" is not your typical night job. It's not a job at all, really. It's a prison. Again, that's just a metaphor. What it really is, is a sub-realm existing within our own that will pull certain people into. It has only been discovered since 1955 according to leaked logs from Paranormal Investigation organizations. Only several witnesses of The Nightshift have come out with their mind in tact. Most victims are unable to give a clear report on what they saw or felt while inside the realm and many have been sent to mental institutions. Eight victims since 1992 still remain in rehab.
The Nightshift represents the plane it co-exists within but in a demented state. The ground may give out from under one's feet or buildings may turn inside out. It's confirmed the realm has its own weather but it only moves from one storm to another. Heavy winds or rain are the norm of these events. Every now and then, however, there will be a calm state where everything feels still. The Nightshift has its own (apparently) sentient beings that, for lack of a better word, are demons. Some look almost human while others look completely alien. Clumps of real-world objects may move around on their own but are no more intelligent than a jellyfish.
Currently, The Nightshift realm poses no direct threat to our own. An arcane expert in Nerva Archipelago argues against this. He referred to an incident where a group of Longbow that went MIA and showed up weeks later. They acted as vessels and mouth pieces for an unknown entity. They were succumbed into private rehab where they died the next day. Forensic scientists recovered colorless shards from their corpses. These shards were contained until a nightshift demon was brought back to the same facility. The demon and shards shared the same readings as one another. Ever since then, exploring the NightShift has been prohibited. Ignoring it won't make it go away, however.