The Darkened Heart

Next came the scorching, for which this book is named. It was not an emotionally driven occurance, not at that point. By then their anger had subsided, no, it was worse than a fitful burst of anger, it was calculated. We called them the Blessed Plains, but... by the time they were through, there was nothing but ash and dust.

— An exerpt from the Bystander's View of the Scorching

They say that the plains of Nolan'Nurr, the Badlands, were not always so... Bad. Adventurers diving through ancients ruins have found farming tools that would suggest that, at once point, there were fields of wheat and other crops that ran all along the mountains.
Yet something destroyed it, burnt the fields to the grow and razed any structures that remained standing.
The Badlands have always confused the academic, by all logical reasoning, there should be anything but dry desert along the mountains. Warm air rising should drop its moisture as rain, which it does, causing mass flooding across the plains, yet still nothing grows. It is as if something still lingers, something filled with an unrelenting malice, something that oozes hatred into the ground, poisons it with a Dark taint.

Historical Basis

At one point in time, there was a battle between two strong groups, one group, referred to in the quote as "they" apparently won, and, in an act of spite, corrupted the Blessed Plains with a Darkened Heart, one that would prevent the once thriving ecosystem from returning.

Spread

Nearly all evidence of the event has been erased. The number of people who know about the myth is likely somewhere within single digits. The only remaining piece of evidence is the book: "A Bystander's View on the Scorching" which only provides a brief explanation of what appeared to be happening, from, well, a byanders view.