In the summer of 1909, the gruesome murder of nineteen-year-old Elsie Sigel sent shock waves through New York City and the nation at large. The young woman's strangled corpse was discovered inside a trunk in the midtown Manhattan apartment of her reputed former Sunday school student and lover, a Chinese man named Leon Ling. Through the lens of this unsolved murder, Mary Ting Yi Lui offers a fascinating snapshot of social and sexual relations between Chinese and non-Chinese populations in turn-of-the-century New York City. Sigel's murder was more than a notorious crime, Lui contends. It was a clear signal that attempts to maintain geographical and social boundaries between the city's Chinese male and white female populations had failed. When police discovered Sigel and Leon Ling's love letters, giving rise to the theory that Leon Ling killed his lover in a fit of jealous rage, this idea became even more embedded in the public consciousness. New Yorkers condemned the work of Chinese missions and eagerly participated in the massive national and international manhunt to locate the vanished Leon Ling. Lui explores how the narratives of racial and sexual danger that arose from the Sigel murder revealed widespread concerns about interracial social and sexual mixing during the era. She also examines how they provoked far-reaching skepticism about regulatory efforts to limit the social and physical mobility of Chinese immigrants and white working-class and middle-class women. Through her thorough re-examination of this notorious murder, Lui reveals in unprecedented detail how contemporary politics of race, gender, and sexuality shaped public responses to the presence of Chinese immigrants during the Chinese exclusion era.