“Jazz Age Mexico hums, but Casiopea Tun is stuck scrubbing her grandfather’s floors, dreaming of escape. A hidden box changes everything: she unleashes the Mayan god of death, who demands her aid to reclaim his throne from his treacherous brother. The bargain is stark—fail and die, succeed and be remade—as Casiopea races from Yucatán’s jungles to Mexico City and into the Mayan underworld.”