Deep in the endless tunnels of a subterranean cave, an ancient species lies patiently in waiting for the creatures of the surface to step out of the sun in director Richard Pepin's horrific voyage into the black pit of the unknown. Rumor has it that a vast treasure lies hidden deep within an abandoned mine that sits just atop the vast system of caves, and a group of brave adventures are determined to claim the mythical prize for themselves, if it does in fact exist. But something far more sinister awaits the unsuspecting treasure hunters beneath the surface, and as their harrowing journey takes an unexpectedly terrifying turn, they soon discover that humankind is no longer at the top of the food chain.