Falder and Lendi are God Keepers, engineer priests who control the ancient nanotechnology powering civilization. While Lendi dreams of fleeing for a life of adventure, devout Falder is desperate to keep his best friend from abandoning their order—and him. But when a technological god returns in a ball of fire and grey death, it severs Keepers from nanotech, plunging the world into chaos.

Far from the order’s influence, Sedna and Renfrik are skilda, sworn guardians of a village destroyed in the god’s wake. With nothing left to protect but themselves, they seek answers from the Keepers and revenge against the god. Cities burn, and new epicenters of spreading death bloom across the land, changing everything to grey dust.

To hunt the deity and restore the Keepers’ power, the foursome must set aside their suspicion, pride, and even faith. Failure means dooming the world to divine wrath, but reestablishing the Keepers’ power—and learning the dark truth behind it—will force Falder and Lendi to choose between saving their friendship and fixing a shattered world.