In Montreal, a motorist witnesses a woman falling or jumping from a tenement building. Police arrive on the scene and find a crucifix and a small metal pyx gripped in her hand. Widowed detective Sergeant Jim Henderson is assigned to the case, and soon determines the woman's identity as Elizabeth Lucy, a heroin-addicted prostitute. Henderson determines that the apartment she leapt from was unoccupied, and that the building also serves as a brothel operation. Leading up to her death, Elizabeth, a lapsed Catholic, was struggling to get her life in order.