Plane i

Plane i is a point on the theoretical dimensional z-axis. There are two major hypotheses regarding this plane—known as the Gladius and Fourth Wall Hypotheses, respectively. Neither concept has yet been proven.

Gladius Hypothesis
Lord Gladius, the present Gatekeeper of Dimension Alpha, invented the present z-axis theory; and even he will admit that to some extent he did so to allow for the possibility of a complete convergence point—a dimensional plane where all realities within a dimension meet. He claims that there must be some way for people to suddenly and unconsciously shift from one reality to an entirely different one, as has reportedly been done several times throughout recorded history.

Fourth Wall Hypothesis
A competing hypothesis, known as the Fourth Wall Hypothesis, is somewhat more accepted than that of Gladius but has no more supporting evidence. This theory treats i like any other z-coordinate, interpreting it as a plane rather than whole point. As with all planes on the z-axis, travel to this plane cannot happen intentionally. However, entities can move freely along the x- and y-axes in this plane—therefore adding an element of conscious effort to unconventional reality-hopping.