The Nature of Reality
Reality in the The Invisibles is like a hologram. What we perceive as the "real world" is actually the overlap of two different dimensions. One healthy dimension, Universe A, is represented by the Invisibles. The other terminally diseased universe, Universe B, is represented by the Archons of the Outer Church.
The Invisible Army is composed of groups of cells who fight the overbearing oppression of the Outer Church. Each cell's member is assigned a position as either Earth, Fire, Air, Water, or Spirit. Each position has it's own duties and can be changed when necessary. The main cast of The Invisibles is one such cell.
King Mob and Ragged Robin's Cell
The Invisibles of 1924
When King Mob travels back to the "Golden Age of Anarchy", he meets up with some Invisibles from that era:
Various real-life people throughout history have also been members:
A sort-of "police squad" that investigate paranormal crimes. They are also members of the Invisible College: