There is a deeper Reality beneath the comfortably obvious.
Space is neither empty nor limitless. The cosmos only seems to stretch forever, from the blackened husks of long-dead stars to the incandescent fury of quasars blazing within far distant galactic clusters. Even the yawning emptiness between such objects is not truly vacant, but hums and keens with the ancient melodies of ionized gas and magnetic fields. The bare vacuum itself roils with fertile acts of creation and destruction, of particles and anti-particles born from nothing and returning to oblivion, all within the thinnest shaved shards of time itself.
Yet it was not always so.
There was a time, incomprehensible to minds constrained by time's invariant arrow and a mere three dimensions, when nothingness reigned supreme. Not emptiness.
Nothingness, Before there was a reality, how could there be existence? Yet time does have a starting point, a beginning. Cosmic symmetry argues an Alpha Time must balance an Ultimate Omega Point. Whether by accident, natural law, or purposeful Design, something appeared where once there was nothing.
Of that mystery, nothing is truly known. Whatever the First Cause, timeless vacancy blossomed into an all-consuming inferno of creation, a totality of what would someday be called matter and energy: a universe.
The first ticks of that time were a blaze of unthinkable energies and infinitesimal motes of mass. Even light was too weak to exist unsundered and free within such an inferno It was a time of new-birthed reality's seeming raw and unfettered rage against nothingness, an enormous beacon attempting to fill an infinite darkness.
But then as now, all things that burn must eventually cool. Entropy remains the final judge and arbiter of this reality. The bright and implacable All immediately began to expand and cool, as it would forever after that first tortured moment.
Photons at last slipped free of creation's incandescent forge, and fled tirelessly across the face of that new reality. A subatomic menagerie met and merged into new and exotic arrangements. Matter was born, and vied with energies both subtle and gross for supremacy; each won in different regions of the expanding space-time continuum.
The new-birthed universe continued to grow, still many times hotter than the core of a sun, but ever cooling. It stretched like the surface of some cosmic balloon under hurricane-driven inflation. Yet the fabric of space-time is not infinitely resilient, nor was the expansion uniform. Under unthinkable stresses, reality itself strained and groaned with the aftermath of creation's bright birth. Ripples and cracks formed in the very substance of space-time.
As fissures form in water rapidly freezing from the liquid state to ice, so was it with the very nature of reality.
These fissures, spiderweb cracks appearing in the expanding cosmic egg as it hatched, were tiny but powerful. Each crack was far thinner than an atom's thickness, yet stretched for many light-years.
The primordial cracks and fissures thrummed and writhed with raw energies and potential. Their tortured movements struck nearby concentrations of hot matter like a fist. Electromagnetic fields crackled and roared along their lengths, inducing strange and intricate patterns in local clouds of glowing gas.
Some of these cracks in creation joined, building gigantic networks of frantic topology. Still others split into smaller fissures, radiating powerful gravitational waves that spread across the new-formed universe like ripples in a pond.
The expanding universe was distorted unevenly by these tangled knots of space-time, a cosmic fork stirring the stuff of stars. Some large networks acted as gravitational foci; seeds for the aggregation of coalescing matter into what would eventually become great seas of stars. These vast stellar whirlpools would someday be called galaxies.
But that lay many eons in the future.
Most of the fissures and cracks in space-time vanished, their substance and power leached away into loud peals of gravitation tolling across the universe. The furious expansion of reality slowed, and the new universe's grand structure unfolded.
Yet some tangles in space-time remained, diminished in glory and potency. Minds which eventually came into being within our universe gave these remnant structures of anguished topology a host of names, in as many languages. Humans would someday call them cosmic strings.
But they are not strings.
They are windows.
The knots and tangles of space-time were tiny connections between the new universe and an entirely different space-time continuum. Minds roamed in that other reality, on businesses unknowable. Such minds were not constructed of the building blocks basic to this particular space-time. The equivalents of their flesh and blood were not composed of quarks and quanta, electrons and protons and neutrons. They were not subject to the forces and natural laws which bind our reality, linking past and present and future. Flavor and charm were not extinguishing characteristics of even their smallest components.
Though strangeness of a comparative sort was implicit in their nature.
However alien, the entities on the other side of the cosmic strings had minds and possessed something much like curiosity. Eventually, they discovered the distorted windows into our reality which are the tattered remnants of creation's first moments of birth. The entities learned that such twists in the fabric of space-time could transmit information.
The minds, completely foreign to any entity living within this space-time continuum, peered dimly through these humming cracks into our own reality. Their curiosity was piqued by this strange place so unlike their own home. That interest kindled and grew as they caught glimpses of a different universe, new modes of existence. Eventually, they wished to explore this alien place, so close and yet so distant.
They could not enter this space-time continuum, any more than a human being could enter and live within a printed page. But they possessed a drive to explore – even by proxy.
The entities investigated this space-time continuum in the only manner they could. Tentatively, they reached out to the cracked windows at the border of their own reality.
And beyond, into out own.
Call the minds that moved in that other universe They Who Pass.