In an alternate New Orleans caught in the tangle of the American Civil War, the wall-scaling girl named Creeper yearns to escape the streets for the air—in particular, by earning a spot on-board the airship . Creeper plans to earn Captain Ann-Marie’s trust with information she discovers about a Haitian scientist and a mysterious weapon he calls The Black God’s Drums. But Creeper also has a secret herself: Oya, the African orisha of the wind and storms, speaks inside her head, and may have her own ulterior motivations. Soon, Creeper, Oya, and the crew of the are pulled into a perilous mission aimed to stop the Black God’s Drums from being unleashed and wiping out the entirety of New Orleans.