Of creatures great and small
The Omen Plague has other names. It is known as The Star Plague and even The Mundane Plague. It is still with us today, now known by the common name of the Shaking Death. To set the stage, the stars were aligned in all the wrong signs. Everyone new something bad was going to happen. When winter set in hard and early, they thought that was it. They were wrong.
Real world scientists have accidentally opened a tear in the fabric of reality, transporting their laboratory into the game world. Unable to repair and/or refuel their equipment in this (to their minds) primitive world they are now trapped.