Deep Below

Fate decreed that none may bury deep beneath the ground. The why is not entirely known, though many have their own theories. Within the Island Nations specifically, many have debated it. Fates Hand cares not for the why, as it does not matter. Fate has spoken, and must be obeyed, and those that refuse will be struck down like all the rest.
The Tullians, in their ever arrogance, believe it is to prevent people from digging up Lufein technology, for it belongs to them, the Tullians, and no other. The devices deep below the ground clearly will be allowed to be retrieved by Fate in future, by the Tullians, for the Tullians. After all, it is their right.
The Dwarves are the least pleased with this, though they have for the most part obeyed. Amongst their legends is that Deep Below, great breasts and monsters exist, and if too many dug too deep, it could unleash these creatures upon the land, causing chaos and death.
The Northern Empires general belief is not known, though they follow it diligently. Rumour has it that some of the North have secret mines operating, plumbing the depths, operated by the Fateless, whom Fate cannot control. If these operations are real, Fates Hand wishes to destroy them, both for refusing to obey, and to destroy the abominations operating it.
The Elves talk of ancient legends, of something from the stars buried below the ground during the Starfall, and that if it was unveiled, could upturn the world as we know it. Such secrets must be protected at all costs, until such a time comes that it can be revealed to all.
Whatever the truth may be, none have buried below have returned, not even the Fateless. Something dark lies below.