The Hollow Quarry Vault

Five miles down, the sunless city of Batu Deep breathes through iron pipes. Steam compressors roar on the surface, feeding the pneumatic drills that chew limestone for a greedy empire. Drill Boss Lana doesn't care about imperial ledgers; she just wants to keep her union crew alive through another grueling, bone-rattling shift. But when her drill bit cracks open a pitch-black geode, she doesn't hit stone—she hits something that shrieks back.

An armored, rock-swimming horror tears out of the earth, its ultrasonic cries liquefying load-bearing limestone pillars into rivers of deadly gravel. As five-hundred-ton boulders rain into the streets, tightly-wound company foreman Budi scrambles to save his precious machines and exhausted marshal Rian battles frantic riots in the dark. With eccentric occult scholar Dewi mapping the beast's deliberate path of destruction, Lana must turn the tools of her grim trade into weapons. If she cannot vent the pneumatic network and shatter the entity with perfectly tuned harmonic charges, the cavern's ceiling will collapse, burying forty thousand screaming souls under an ocean of crushed rock.