By 
quarkstomper
Keywords
The Adventure Seed
In the 1970s, the US Military constructed Project ELF, an experimental communications station in the deep woods of Northern Wisconsin. It’s stated intent is to communicate with submarines by utilizing the Earth’s crust to transmit Extremely Low Frequency radio waves.
What is little known is that one of the first times it was actually put into operation, there was a lightning strike which created a tremendous power surge, and a stone sarcophagus , apparently late Roman in origin, appeared at a nexus point between the transmitting towers. The coffin bore on its lid a diagram of the ELF antenna array and a Latin inscription translating as: “That which is Strong Survives”.
Further research revealed that the system was capable, under the proper circumstances, of creating a portal to another timeline; one in which North America was colonized by Imperial Rome.
The Government stifled this discovery and ultimately shut down the project; but the antennae and the equipment still stands. But recently, someone has been using it. Strange aurora borealis have been seen in the night sky near Lake Superior and Roman Legions have been spotted near the Upper Peninsula. In the Bering Strait, a nuclear submarine disappears and strange radio interference blankets the upper Midwest.
You have come in contact with a scientist who has learned the truth. The Roman sarcophagus contained the body of a heretical priest of the Old Ones and the ELF system replicates his plan to reach across the realities and bring the Elder Gods to our world.
Someone is trying to complete the priest’s plans, causing multidimensional chaos. Is it someone in the Military? A madman who worships power? Someone from the Alternate Timeline? Or perhaps the Elder Gods themselves, sending their thoughts across the dimensions? All you know is that you are the only ones who can stop it!