From the Introduction:
There are many worlds beyond our own. While the imagination and knowledge looks to those worlds beyond out own solar system, the truth is that there are an infinite number of parallel worlds existing alongside our own world.
For a vast majority of human history these worlds were closed off to us. Not only were they closed to us, but we were entirely unaware of their existence. On November 27, 1933 this changed. At 3:42 PM. When Leon Theremin created the first gate (as they became known) to another world in his New York laboratory. This first gate was unstable and lasted only a short time. During which a white pigeon came through the gate. Theremin initially believed that he had created a portal to another place on Earth. During subsequent trials several of these gates opened to views that were obviously not Earth, though nothing came through the gates after the white pigeon.
Theremin's experiments were observed with keen interest by groups within the United States, Russian, and German governments. In January 1936 Theremin's lab was ransacked and most of his equipment and notes were taken. By the end of the year there were rumors that Germany had been experimenting with their own gates.
Theremin beguan to work with a number of American scientist on new versions of the gate. One of the primay problems with the gates was that they were inherently unstable. Constant adjustments needed to be make to keep the gates open, and even Theremin could only keep a gate open for 10-15 minutes before it would collapse.
In 1938 Theremin disappeared from the United States. His wife, Lavinia would report that a group of "Russian Men" had appeared and kidnapped him. He fate would not be know until 1990 when he was discovered living in Moscow by French tourist who had known Leon Theremin during his time in New York. He would not speak of what had passed in the intervening time, but after the fall of the Soviet Union papers were discovered that implicated he was involved in the Soviet gate program as well as developing technology related to espionage.
During the second World War Allied Intelligence out of Germany seemed to indicate that not only had Germany developed a method for stabilizing a Theremin Gate, but that they had discovered allies on the other side who were providing the German army with advanced technology. In a daring OSS mission in 1943 it was discovered that while German scientists had not developed a method of keeping a Gate stable, they had developed a method of reliably opening a gate to the same place repeatedly. The OSS were able to steal this information as well as destroy the prototype gate machinery as well as any information left behind. While it was true that the German scientist had managed to open a gate reliably to the same location multiple times, the gate opened to a barren, lifeless world which had no atmosphere. No evidence of otherworldly allies was ever discovered.
During the Cold War the United States as well as the Soviet Union spent a great deal of time and money on the gates, the gates remained more a novelty than anything useful. Neither side was able to stabilize the gates.
In 1983 a body was found in the hills above San Juan Bautista, California. Identification on the body indicated it had been a man named Daniel Green, an electrical engineer in the Silicon Valley. Dental records confirmed his identity. There was one problem, Daniel Green was very much alive living with his wife Deborah in San Jose, California. The living Daniel's dental work exactly matched that of the dead Daniel. Authorities were baffled. Several months after the discovery of the corpse, Daniel Green had an apparent mental break down and was committed to Coalinga State Hospital. During his treatment an unbelievable story came out.
Daniel Green was not from our world. He was from one very much like it with only minor differences. One of which was that in his world his wife Deborah had been killed in a tragic car accident. The Daniel Green from this other world had crossed over into ours, murdered this world's version of him, and taken his place. Over time though, his guilt about what he had done coupled with the minor differences between our world and his had caused a mental collapse. While most of the world believed that Daniel Green had simply lost his mind, groups within the United States government caught wind of the tale, and became concerned. A man had crossed over to our world from another, and committed murder. While this incident did not have vast repercussions, the possibility of something more severe occurring put into action the formation of the Gate Management and Intelligence Service. The GMIS was tasked with researching the gates, developing methods of detecting them, and managing any incursions into our reality.
In the 1989 the GMIS developed reliable method for detecting and pinpointing gate activity. It was determined that Gate activity was very uncommon. Between 1989 and 1999 only 7 gates were detected. In only one case, in 1996, did anything cross through, and in that case it was a woman claiming to be a political refugee from the Global People's Republic of Greece.
Between 1999 and 2009 gate activity grew at an exponential rate. By 2009 there was an average of one gate opening every month. The GMIS grew in proportion. In addition to managing these extra dimensional incursions and contacts, the GMIS also worked to suppress knowledge of the gates. With enough technical know how and access to any modern electronics store it was possible to build a gate in less than a year.
In 2010 computing processing power had increased to a point the GMIS was able to prolong the life of a Theremin Gate to nearly 24 hours. Using information gleaned from German research during World War 2 the GMIS was also able to open a gate reliably 3-4 times in the same location before losing the location.
2012: Modern day. GMIS continues to monitor gate activity and manage incursions from other realities. The GMIS also monitors the creation of gates by civilian entities.
This game is envisioned that the Player Characters are members of the GMIS working to control incursions from other realities. Most of these incursions are relatively harmless. They are human explorers or political refugees. In these cases the GMIS will offer refuge, or attempt to find out if the explorers know anything useful to the GMIS or pose any sort of threat, and then send them on their way. Other incursions are decidedly less benign. They are people like Daniel Green, or worse, criminals feeling the consequences of their crimes, or a new world where they are unknown, and can begin a new life of crime. Some worlds use the gates to dispose of hazardous materials and extremely dangerous people. Sometime the visitors from the other world are decidedly not human and their intentions incomprehensible to humans.