The year is 1926 and Shanghai is ruled by two rival gangs—the Scarlet Gang, led by eighteen-year-old Juliette Cai, and the White Flowers, led by Roma Montagov, her first love and first betrayal. When gang members on both sides begin clawing their own throats out in a mysterious frenzy, whispers of a monster in the Huangpu River grow impossible to ignore. To stop the madness, Juliette and Roma must set aside their guns—and their grudges.

Juliette Cai is fiercely proud and dangerously capable—a former flapper who returned from New York to claim the Scarlet Gang's throne, only to find the role more complicated than she imagined. She is ruthless when she has to be, but the cracks in her armor reveal a young woman terrified of losing the city she calls home—and the boy she never stopped loving.

Across two novels set against the backdrop of 1920s Shanghai, the series escalates from a supernatural plague to outright revolution as the Nationalists march in and gangster rule faces annihilation. Juliette and Roma are pulled apart by loyalty, pride, and deliberate sacrifice before the city's fate forces them together once more. The duet is a Romeo and Juliet retelling that subverts expectations about who gets to choose their ending, weaving themes of identity, belonging, and the weight of legacy.