We were crossing a ridge when Corgan was lifted off the ground by something. "Shoot it! Shoot the tyrannosaur!" he screamed as blood streamed from the puncture wounds that had opened up in belly. I fired into the empty space above him to no effect. Then Corgan's ragged corpse dropped to the forest floor, and I was alone. Utterly alone. There was no dinosaur. There was nothing.
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.