The Mound by H. P. Lovecraft and Zealia Bishop

An explorer in Oklahoma discovers a strange burial mound and uncovers an ancient tunnel leading deep into the earth. Within, he finds an underground civilization untouched by time but ruled by alien gods and bizarre customs. The plot follows a written account by a doomed Spaniard, whose fate reveals the cost of venturing too deep. A richly detailed and epic horror tale blending archaeology, cosmic dread, and forgotten history. A terrifying descent into a hidden world that was never meant to be found.