IstEridanë

IstEridanë, known in the common tongue as "halflings," were a species of diminutive humanoids that coexisted with the IstErillen and the IstErinin for many thousands of years before being wiped out by a cataclysmic plague known as the Wastrel's Reckoning.
In contrast to the pragmatic, engineering-minded erinin, the eridanë were much more scholars and artists. Though the two races peacefully cohabitated the mountains of IldRenn, it was not uncommon for jabs to be delivered across the bow, the erinin describing the eridanë as fanciful fools, while the eridanë criticized the erinin for a lack of imagination. Despite the fond rivalry, the two races got along quite famously and their civilization prospered for it.
Unfortunately, it was the grand ambition of an eridanë that would ultimately spell the end for his people. Before his time, though the erinin, erillen, and eridanë lived within the mountains, they only occupied natural caves near the surface. His vision was of a civilization that reached into the very bowels of the earth, cities atop cities, leading ever deeper into the heart of the world.
This dream would grip erinindal and eridandal society like a madness. Though he would not live to see the first of the grand cities he'd envisioned, the first dwarvenhold was finished and dedicated to his memory a century and a half after his death.
What this eridanë visionary, and all the erinin and eridanë that had participated in turning his dream into a reality, had failed to account for, was the sanitation requirements for such an endeavor. As those responsibilities fell to the erillen, who were viewed as second-class citizens of their great civilization, little consideration was made toward those concerns. While the erinin and eridanë remained blissfully unaware of the looming danger, the poorly planned waste-management systems were breaking down. In the end, this neglect spawned the plague that would see the eridanë forevermore entombed in the dwarvenholds they'd helped to build.