R.B. Hask

A cave-diver must drop into an inverted subterranean world to poison its megafauna nursery, while an apex hunter from below must climb the reverse-gravity cliffs to slaughter the ceiling-clans for their obsidian. Two worlds face each other across a thousand-foot vertical drop, where gravity reverses precisely at the midpoint. Sorcha is a ceiling diver who treats mercy as a lethal luxury, and Ruiseart is a brutal floor-realm hunter determined to strip the upper world of weapons-grade glass. As their desperate realities collide over starving clans and exhausted resources, they will shatter the chasm itself.

Oshuro is a pit of red mud and black glass, carved into an active volcano that keeps the endless ice age at bay. In the fighting terraces, survival is measured in razor-sharp obsidian. Tadashi is the best knapper in the crater, crafting thermal prism blades that slice through bone and stone alike. He cares nothing for the warlords squabbling over the heat vents—until an army of starving raiders breaches the rim, determined to seize the thermal core. To stop them, Tadashi must ignite the deep magma flues. Winning the siege means scorching half the terraces he calls home, and his neighbors would rather kill him than starve in the dark.