Fracture

The fracture was the event that sparked the Big Bang, accidentally set off by the advanced ancestors of the invaders who terrorized Sean Clements's world.

The Singularity, the Collapse, the Fracture
The universe held all dimensions on a plane of singularity. All existence, every dimension, contained within an infinite flat plane. It was infinitely deep, with infinite volume, yet no mass or measurements. The dimensional rifting allowed for literally anything to be possible. A race of existential technologically advanced beings with no form or mind evolved so high, that after a period of time that never took place at all, they tapped into the interwoven structure of time and space and other prospects that we could not comprehend. As they did, a single mistake resulted in an event known as the Collapse. A universal cataclysm that resorbed everything everywhere known as the Collapse occurred. The Collapse was followed by a much more famous event known as the Fracture. It split, fractured. The universe blew into an infinite amount of pieces, each a self contained universe, with different sets of laws and physics. Dismayed and horrified, the surviving creatures tried to make a machine that could undo their mistake. Instead, they found they could not because the dimension they were stranded in made this technology impossible. So they built portals to other universes, and constructed the various parts of their machines there. They linked through the portals, and they nearly completed their mission until Sean Clements "wiped their slate clean and dumped them down the tube." The creatures were left to drift in their dimension, hopefully starting over and abandoning this ridiculous pursuit. When they encountered other races, they possessed them to build the portals, so they could cross. Without living creatures capable of construction, this would never have achieved fruition.