Bill: What do you mean, "it's a literary high"?
Joan: It's a Kafka high. You feel like a bug.
- Naked Lunch (1991)
Bug Powder is a strange magical substance found in the City, and its world, and possibly elsewhere. It generally appears as pale yellowish powder, and its official use is as a professional-grade insecticide. It can be found in containers from several different and mysterious suppliers--"Benway Chymical", and "Voke & Veech", are prominent examples. Bug powder will indeed serve as an insecticide, but if nasally insufflated (snorted), or injected intravenously in small doses it has euphoric and mild hallucinogenic properties.
Long-term use generally leads to dependence, but also, like use of a large single dose, seems to open a doorway to another plane. Users report travel to an exotic, desert world under two reddish moons, were lies a sprawling pennisular city called Interzone, on the quivering banks of a gelatinous sea. The swarthy inhabitants of Interzone appear human in all respects, but have undefinable and unsettling air of strangeness about them. In addition to the natives, humans from many time periods and worlds, as well as alien beings, can be found sweating in Interzone, perusing their own agendas. There is a great deal of political intrigue in the city-state, and several different political factions--but the goals of these groups and the reasons for their conflicts often seem contradictory, if not outright nonsensical.
Mystics and planar scholars believe Interzone to be an interstitial realm acting as a gate or "customs station" between the material world and the inner planes. Supporting this view is the presence of soldiers the Hell Syndicates, as well as miracleworking street-preachers and holy hermits professing the varied and conflicting "ultimate truths" of the Seven Heavens. A slight variation on this view, is that Interzone is not so much a part of the astral plane, but more an extension of Slumberland, the Dream-World, located in some seedy Delirium ghetto. Further exploration will be needed to determine this for certain.
This exploration isn't without dangers. While physical dependence comes from the bug powder's use, the thinning of the psychic barriers between the material world and Interzone serve to cause a person to involuntarily shift between the two. This tends to generate feelings of paranoia--and perhaps rightly so, as the more time one spends in Interzone, the more likely one is to become an agent (perhaps unwittingly) of one of its factions, and fall prey to its byzantine intrigues.
One final interesting bit of Interzone lower is that the natives hold that their city-state, was actually once six cities of very different mystic character, physically indistinct and loosely co-spatial, but still spiritually differentiated. The names of theses putative cities when uttered with the proper ritual, are said to be a powerful spell, though sources disagree as to what purpose.