When the police do nothing to solve the murders of three prostitutes knifed to death in 1866 Sicily, Serafina Florio, a struggling widow with seven children, unmasks the killer, but not before uncovering burdensome truths of her own.  It is six years after Unification and Sicily is in chaos. Bandits rule the hills. Waves of cholera kill thousands. The Mafia begins its vicious reign of organized terror, raping a population squeezed by conscription, crippling taxes, and corrupt officials. At a high-class house near Palermo, three prostitutes have been knifed to death, their foreheads slashed with a strange mark, their bodies dumped on the madam's doorstep. When the chief inspector does nothing to solve the case, the madam summons her lifelong friend, Serafina, and asks her to catch the killer. Serafina is a midwife, but she decides she must help. She plunges into the investigation, gathering evidence, following leads. She meets with relatives and friends of the deceased and discovers a thread common to all three victims. After a fourth victim is strangled, Serafina's hopes for a quick resolution are dashed. Her emotional low is short-lived, however. In a defiant meeting with the Mafia don, she makes an important discovery. Convinced of the murderer's identity, she conceives a daring plan and, with the help of her daughter, corners the killer, a wild one bent on revenge. But will she have the strength to save herself and her loved ones?