The "Hall of Mirrors" effect (HOM for short) is a known"feature" of games based on the DOOM engine. Basically, if you step outside the game's map it does not know how to draw the environment, and the results are bizarre. Here are some examples of what Our Heroes might have seen. Is it any wonder they didn't like it out there?
You can get seasick just standing still.
A whole new perspective on game playing.
Sometimes you can almost see where you are, but it still gives you the jaggies.