Since ancient times, certain humans have been immortal. In later centuries, they would learn the reason: an infection by a strain of the "Progenitor virus". Aside from longevity, the virus conveys a healing factor, immense physical health, and silvery eyes. The virus conveys immunity to many diseases - it will immediately infect and neutralize microbes, for example - but does significant damage to the gut flora, leading to significant chronic pain.
Many immortals are angry at their condition: they will live forever, and suffer forever. Some manage to kill themselves, despite their resilience. Others form cults, or are overthrown by fearful mobs. Eventually, several immortals banded together to investigate their condition, and if possible cure it - if that meant death, at least they would know peace. They submitted themselves to investigation by Faraj ben Sālim, the Sicilian-Jewish physician and translator. In 1281, thanks to the ability to dissect and analyze a human body while it still lived and spoke, the group made a breakthrough. Though they do not speak of it, the group found a way to cure their endless pain and live normal lives. They banded together, taking the name Da'ath, or "knowledge" in Hebrew, swearing to become masters of the living world.
In 1718, a member of Da'ath manages to experiment with the Progenitor virus. He infects medicinal leeches with his own blood, which when applied to a human corpse could give it a temporary un-life. His story later forms the basis for Mary Shelley's story "Frankenstein".
In 1858, Charles Darwin and Alfred Wallace introduce the theory of evolution: genetic descent with modification due to natural selection. Virchow, Schleiden, and Schwann develop the components of cell theory around the same time. The Victorian zeitgeist takes such discoveries in strange and unexpected directions. "Social darwinism", a term invented in the 1880s, claims that "survival of the fittest" is a suitable template for society, not merely a description of natural selection. The Contagious Diseases Act is passed in 1864 and confines women accused of venereal disease to "lock hospitals", disproportionately affecting the female working class of Britain. This conflation of morality and biology continues as a theme throughout the Victorian era.
This mixing of science and sociology comes to a head in 1893, when Professor Emmanuel Hildern elaborates his theory of evil as a transmissible plague and proposed, effectively, a vaccination against it. He bases his theory on the discovery of a humanoid but non-human skeleton, which develops tissue when exposed to water. Hildern is eventually locked away in an asylum run by his brother, and no further sign of the skeleton is found after a heavy rainstorm.
According to Darwin's theory, biological mutations can arise by chance, then spread broadly throughout a population. A radical change to the environment can be sparked by a single surprising event. History sometimes works in a similar fashion, and one particular spark came about because of a king and a writer.
In 1862, King Otto of Greece is forced to abdicate the crown. It is offered to Edward Bulwer-Lytton, the English novelist, poet, playwright, and politician. Bulwer-Lytton is a noted Hellenophile and his books have been well received by the public for years. Along with the offer, Bulwer-Lytton receives a startling secret. Shaken by what he is told, he declines the honor and returns to his work. Four years later, he is elevated to Baron.
In 1871, Bulwer-Lytton writes a fictionalized version of the secret he was told, called "The Coming Race". This novel features an unnamed narrator who discovers a way into a subterranean world. This inner Earth is populated by a people called the "Vril-ya" with telepathic and parapsychological abilities. Their civilization and powers are attributed to mastery of a mystical substance called "vril", analogous to electricity in its variety of applications.
The concept of "vril" is seized upon by a number of occult thinkers, including Rudolf Steiner, the literary critic, esoteric writer, and founder of Anthroposophy. Steiner's thinking separates him from his original comrades in the Theosophical movement, as he is more interested in developing a philosophy that incorporates natural science than following Theosophy's mystical mindset.
The Wahrheits Gesellschaft, or "Society for Truth", emerges as an inner circle of the Thule Society in 1911. The Society for Truth's members have read "The Coming Race" and other sources, and conclude that it is based on a true story. They begin searching for tangible evidence of vril, driven by Steiner's naturalistic approach.
In 1927, Robert Olmstead visits the New England town of Innsmouth, as part of a search for details of his own family line. He speaks with town drunk Zadok Allen, and learns the secret history of the town. An intelligent non-human species, the "Deep Ones", live under the sea, and periodically come to shore to breed with human beings. Almost everyone in Innsmouth is now a human-Deep One hybrid. Alarmed by this discovery, Olmstead approaches the Federal authorities with convincing evidence, causing them to send submarines and soldiers to Innsmouth. A general cleanup of the town occurs, driving the Deep Ones further under the sea. Olmstead himself commits suicide shortly thereafter, puzzling most members of his family.
Officials who obtain the corpses of Deep Ones compare them to the 1893 writings of Professor Hildern, and conclude that his "mysterious evil skeleton" was in fact a Deep One. The alarming conclusion is that the creatures must have existed for at least 80,000 years.
Josef Mengele, the infamous Nazi doctor, joins the Nazi Party in 1937, and the Schutzstaffel (SS) a year later. Heinrich Himmler, leader of the SS, was a noted esoteric and member of the Thule Society. Himmler's mystical leanings aren't of interest to Mengele, but some of the hints uncovered by the Society for Truth and spoken of by the SS high command - such as unusual human genetic potentials - fascinate him. He begins a series of monstrous experiments on prisoners during the war, unhindered by any sort of ethics or morality. He is assisted by other geneticists and scientists, among them Brigid Tenenbaum and Henry Jelliff.
Mengele and Jelliff escape the fall of Nazi Germany in 1945 and move to Paraguay. They continue their research into human cloning. The Battle of Berlin ends May 2, 1945. Only July 9, the day a partial solar eclipse occurs in Berlin, Brigid Tenenbaum finally uncovers evidence of vril in a secret laboratory.