A World Above The Underneath by Christian H McGhee

I want to take a moment to acknowledge all of my American readers. Without you, I would have stopped tapping out these stories many years ago. Twelve thousand Thank You's and a Million God Bless!What's causing all these sinkholes?Once the planet became unsustainable, Humanity had no other choice but to burrow Underground and begin anew, leaving behind only traces of a once great society. Now, centuries later, two vastly different civilizations have evolved to inhabit the Earth, each one completely unaware of the other's existence. As scavengers and tribes struggle to survive amongst the ancient ruins that clutter the surface, thriving communities continue to advance in an ever-expanding world located less than three kilometres underground. However, people living in these caverns now face a new environmental disaster that if not corrected, threatens to wipe them out once and for all. Join Historia Artifact—Libertines only official Archeologist—as she roams through an apocalyptic wasteland, searching for a better life to offer her kids. Through happenstance, and by way of a large sinkhole, she finds herself trapped below the surface in a world that isn't her own. Now, she must build alliances and navigate through a hostile society that wants nothing more than to deny her very existence. Historia's kids may never see their mother again, unless she finds her way back to a world above the Underneath.