Absolution Gap

The Absolution Gap is an enigma. No one really understands how it works, but it appears to be an immense... gap in reality. The gap itself has no physical traits, it's merely non-reality, a state of nothing between two halves of the universe.

Expanse
The Gap surrounds the entire Second Gigaquadrant. It is not known exactly how massive it is, because no one has ever traced the entire thing out, but galaxies far from each other (as in, other ends of the gigaquadrant) have all encountered it, so it is assumed to be an extra-gigaquadrental structure.

Crossing
There are openings and passages through the Gap, called "bridges" only because it helps creatures comprehend their purpose. They allow travel from one side of the Gap to the other, but are unstable, you can only ever use one once. After the first time, it will collapse behind you and you will need to find a new way to cross over the Gap.

Appearance
The Gap has no physical form, and can only be sensed by the fact that it is a hole in reality. You can enter it anywhere, but unless you happen upon a bridge, you will vanish into the void that is created by the Gap. As of yet, no one has actually been able to "see" the gap, no more then you can "see" a black hole.