Omniverse Agents are field operatives of a highly advanced parallel universe Earth whose people have mastered inter-universal transit. These agents explore the myriad parallel Earths for a variety of purposes.
There is not one infinite universe, instead there are an infinite number of universes. These universes lie parallel to each other in a six-dimensional continuum: three dimensions of space, and three of time. The dimensions of space (height, width, and depth) are familiar. The linear motion of time (past-present-future) can be considered one "dimension" of time. Time's other dimensions are made up of probability fields that are the "height" and "width" of time. In essence, these temporal dimensions encompass every possible past, present, and future that could exist, and does, "elsewhere" in the continuum. In these higher temporal dimensions lie a potentially infinite number of parallel universes. The amount of divergence between universes - essentially the difference between their "probability valency" - determines how "far apart" they are in temporal terms.
Everything in a particular universe resonates on a quantum level with a unique probability valency. This probability valency is a constant. It cannot be changed by any known process. It is the basic foundation of existence. The probability valency is sort of a blueprint, a script, of its entire universe; the movements of each and every one of its particles in every moment of its time. The more alike the probability valencies are between universes, the more alike the universes themselves are. Minute differences in signatures don't drastically differentiate a timeline on the long term. This causes many universes to duplicate each other on a macroscopic scale, with altered events and personalities on a smaller scale.
Some events and individuals often appear duplicated in these universes despite the larger-scale historical differences between them. Certain events are "synchronized" between the universes so they move in a parallel manner with different moments having their equivalents in various universes. Although the patterns of events move in similar manners in different these universes, the intentions and characterizations can be vastly different.
Thus even on different Earths whose histories diverged decades or even centuries ago, many of the same people continue to still be born because despite the historical divergences similar probability valencies cause the same groups of people to often meet in the same place and time in various universes and the exact same genetic material to be combined to form the exact same next generation. Of course the personalities of the people are often very different than in other universes because they grew up in different conditions.
Although most of the myriad parallel Earths are echoes of the same basic blueprint, each Earth is different in some fashion from the rest. There are some that have never known Humankind, and where this is the case there has never risen another lifeform of comparable intelligence to Humanity. Across the parallels inhabited by Humankind there are many variations of history. Almost all share the Eastern or Euro-Asian continent as the cradle of whatever civilisation they have.
The Earth known as "Earth Zero" developed along one of the five standard historical templates. Rising to a Middle Ages which saw the rapid growth of the Holy Roman Empire, the Germanic states were strongly united in an unusually coherent and effective alliance. Their rulers, and later the World Emperors, maintained a continuity of lineage and policy for nearly five centuries. Dominated by this Empire neither England, Spain or France developed into major powers. The Ottoman Empire briefly opposed the Holy Roman Empire; the resulting Thirty Years' War served only to sharpen the technological revolution begun by Gutenberg and the medieval alchemists. Through a lengthy process of war and diplomacy the Empire rose to world domination. By the end of the seventeenth century the "Boy Emperor", Frederick X, the puppet of a decadent and glittering court, held sway over the entire globe.
There had, during the Empire's long climb towards misrule, been another power rising. Science had been slowly assimilated, over the last two centuries, as the religion of the masses. The Futurist Renaissance with its new ideals, its reappraisal of the world in the light of scientific thought, and its contempt for the old doctrine and dogma (in which the rule of the Emperor was enshrined) was the movement of the people. And, more importantly, that of the military as well.The world-wide military coup, the execution of Frederick and his court, followed by the establishment of a dictatorship based on the principles of the Advancement of Science was inevitable, merciless, and brief. "I am the Son of Scientific Thought", declared the first World Consul, Napoleon Bonaparte, when the world was finally brought under the Futurists' rule in 1802.
The science of this Earth grew by leaps and bounds, unfettered by the socio-religious prejudice usual on other parallels. By 1800 John Dalton had perfected his Theory of Relativity. By 1820 a man and woman had set foot upon the Moon. In 1850 world poverty and famine had been abolished. And, working quietly in London, the mathematical genius Karl Marx was progressing towards a discovery which would change his world. He was constructing a mathematical model, at first of the universe, then of the "omniverse" his equations predicted.
In 1881 he had his proof. Later, he proposed the annotation system still used on Earth Zero to designate different continua. His own Earth was taken as a norm, thus 00-00-00 for Earth Zero; so 00-01-00 and 00-00-01 would be flanking parallels, one unit of "probability valency" removed, and so forth. Marx announced his discovery to an Earth much changed from the iron rule of science. Over the last century, the dictatorship had mellowed into benevolent rule. In 1900, this dictatorship and the powers of the World Consul were dissolved by the Athens accord and the World Government was established. Earth Zero had become the first technologically advanced Earth to live in harmony with itself.
One of the first acts of this new administration was to initiate the "Omniverse Programme" to research the status of parallel worlds and technology to travel to them. London was chosen to be the site of the giant "Omniverse Prime" complex, built to house the most advanced technology of the time and the specialists the project required. In the long, hot summer of 1905 the Omniverse Prime complex became fully operational. The researchers would come to discover that although the probability valency of matter cannot be altered by any known means, it is possible to place matter in a state of "quantum probability flux." This causes the affected matter to become "unstuck" in the space-time continuum, shifting into another universe.
Essentially the process involves putting an object into a state of quantum flux matched to the particular quantum resonance of the other universe. The affected matter shifts out of one universe and into the other. Returning to the original universe is a matter of once again placing the object in a state of quantum flux and matching the probability valency of the original universe. This is somewhat easier, since the object's natural probability valency always matches that of the object's home universe.
The means of doing this involves using a "quantum probability vortex", a weak point in the space-time continuum where different parallel universes come in contact. It can be thought of as a kind of keyhole between different universes. Normally, a quantum vortex is extremely small, and short-lived, of little concern to anyone. However, certain high-energy interactions can cause a quantum vortex to grow and de-stabilize, creating a more volatile interface between universes. Exposure to such a vortex can place objects in a state of quantum flux, causing that object to shift between different parallel universes. This method of travel is called "quantum probability translocation."
From these discoveries, the InterDimensional Ship was invented. Fitted with a quantum probability flux generator, the ID Ship is a transportation craft the can essentially teleport between parallel universes. These crafts are all equipped with an invisibility shield that works by bending light around the ship. In 1910, the first group of "Omniverse Agents" began conducting detailed surveillance of various parallel Earths.
In their explorations, the Omniverse Programme was able to acquire various technologies that enabled Earth Zero to make bounds and leaps in their own technological progression. Eventually, they decided to spread the fortunes to other universe. In 1926, Earth Zero's World Government used their advanced technology to help the people of a parallel Earth, who regarded them as gods. They provided them with medical and scientific aid, better communications and weapons, but the people of that Earth were not ready for such advancements, and a world war broke out that killed over a hundred million. Realizing their mistake, the World Government official decreed a policy of non-interference in other universes, mandating agents of the Omniverse Programme to do no more than observe and gather knowledge.
And the Omniverse Agents have continue that policy throughout the decades as they serve as the masters of inter-universal exploration and pioneering adventures across the entire omniverse. To those few outside of Earth Zero who know of their existence, they are legendary.