From the introduction:
The ancient civilizations that lived in caves, often referred to as “cave men”, knew this, that all caves were interlinked into a vast underworld. When men started to build pyramids and ziggurats with cave-like tunnels, somehow, always, there was a door to this underground, no matter how hidden.
All major ground structures that intersect with the underground, whether through a passage, a basement, a dungeon, or sewer – all inevitably connect to the Hallway. The Hallway changes, expands, contracts - every time an earthquake shifts the foundations, construction of some great monument or tunnel system commences, and likewise, the Hallway incorporates it and becomes larger.
We have been to the furthest reaches of space, but not underground of our very planet Earth. Who knows what awaits us down there?
Civilizations may rise and fall, the Hallway will always be there until the end of Earth.
The Dark Hallway is designed to be used on bulletin boards and forums.