 The attractive Sandra Venturi, studying to be a singer at the conservatory of music in the Italian town of Lucca, has a promising career in opera ahead of her; until that time, however, she s content to give public performances in her native town. On the eve of her nineteenth birthday, during a thunderstorm, the young singer leaves the apartment she shares with her mother Nicole Venturi, a correspondent for a major Roman newspaper. Sandra is on her way to a secret rendezvous with a married man: Marco Pierboni, a good-looking industrialist. The latter is killed by gunfire, however, shortly before Sandra arrives at the deserted villa outside the town which they had chosen as their meeting-point. Nicole has no inkling of her daughter s affair. She thinks that Sandra has gone to stay the night with a girlfriend. When Marco s corpse is discovered the next morning, ambitious journalist Nicole senses that reporting this sensational murder case will make her famous outside her local region. The first thing Nicole does is contact her friend Superintendent Stefano Avanzo, who has been put on to the case. During the course of his investigations the superintendent has already called on the family of the murdered man, and has decided that the alibis of the various members of the family are shaky to say the least. Only Matilde, the mother of the murdered man, is above all suspicion. Severa, the family s trusty housekeeper, does her best to help Matilde get over the loss of her son, but all her efforts are to no avail. Matilde decides to find out the identity of Marco s murderer via a woman medium. Nicole, ambitious journalist that she is, is just as eager to solve the murder mystery. However, her initial investigations, which she quietly keeps Superintendent Avanzo informed about, come up against a dead end: clever discotheque owner Milena Bolzoni, the dead man s "official" mistress, has an alibi. That same evening Nicole, who thinks her daughter is at the conservatory, is busy making preparations for Sandra s birthday. However, when the latter s friend Chiara worriedly reveals that Sandra didn t stay with her the previous night at all, as she had claimed, but was instead planning to spend it with the industrialist who was murdered, the alarm bells start to go off in Nicole s mind. She contacts Superintendent Avanzo, who starts a search operation; it is unsuccessful. Nicole, now in desperate straits, draws consolation from the woman medium whom Matilde, the dead man s mother, had contacted earlier on. Thanks to her special abilities, the medium succeeds in "tracking down" the young woman. The magic route leads Nicole close to the mysterious villa. There she sees a body lying motionless on a riverbank: it s her daughter, Sandra. Aghast at the tragedy that has befallen her, Nicole throws her arms around her daughter s dead body. Nicole s colleagues in Rome are starting to wonder why they haven t heard anything from her, and they send experienced journalist Andrea Baresi to Lucca to give them an update on events. He soon finds out more details about the two murders from Superintendent Avanzo; the two seem to be connected, because both victims were shot with the same gun. Nicole s divorced husband Roberto, who left her and their daughter years beforehand, turns up at Sandra s funeral. Nicole, in a kind of lethargic trance, is hardly aware of her ex-husband s presence. A few days later, however, she can t avoid a painful confrontation with him about their past. When Roberto leaves, Nicole, lonely and utterly distraught, makes a suicide attempt. Fortunately it fails. Recovering in hospital, she hears from her friend Anna that because of the sensational nature of the murder case, her daughter has become the target of several slanderous rumours in the press. Now Nicole has an aim in life again: she must rescue her dead daughter s reputation. This fills her with new strength. She decides to take up the dangerous hunt for Sandra s killer all by herself. From her friend Superintendent Avanzo, Nicole learns the identity of several suspects who could have committed the crime for reasons of jealousy: Milena, Marco s official mistress; his wife, Daniela; or Paolo, Sandra s ex-boyfriend. Meanwhile, violence hits the normally peaceful streets of Lucca. Sandra s friend Chiara only narrowly avoids a mysterious attempt on her life one night. With the aid of a medallion found at the scene of the crime, Avanzo gets a lead on who the culprit might be: Professor Carlo Mauri, a teacher at the conservatory. It turns out that the latter is no murderer, though, simply an inveterate voyeur. By way of gratitude for his release, the professor repays the superintendent with a very useful piece of information: he used to be Sandra s neighbour, and on the night of the murder he saw her ex-boyfriend Paolo lying in wait for her before her nocturnal rendezvous; then they both drove off together. When the superintendent arrives, sirens blaring and blue light flashing, at Paolo s place, the suspect just manages to escape from his apartment before the police can arrest him... Nicole learns from Avanzo that recent events have led the police to consider Paolo as the prime suspect. A short while later she gets a phone call from the young man: he protests his innocence and explains that the reason he ran away from the police was because he didn t want to be wrongly identified as the murderer. Nicole, convinced of Paolo s innocence, continues with her investigations alone. She discovers that her own friend, Anna, had actually been the person who first introduced Sandra to industrialist Marco. Nicole now secretly shadows her friend, and catches her making a similar match. She takes Anna to task, and discovers that she has been the mistress of Massimo Pierboni - the murdered man s brother - for years now, and it was he who involved her in this lucrative, albeit immoral, business. An increasing number of seemingly honest people in the town all start to appear dubious. The range of suspects widens more and more. Nicole finds out that Milena, the mistress of the murdered industrialist, and Martelli, his business partner, have been carrying on a fierce blackmail campaign against one another. When events come to a murderous head, and Milena is found dead in her discotheque, the police arrest Martelli as the main suspect. Superintendent Avanzo, however, thinks he knows who Milena s real murderer is: the shady Zappi, who was involved in all kinds of illicit dealings with the disco manageress. Once again, Nicole receives a warning from the superintendent - who quietly sees her as more than just a friend - about the increasing danger of investigating matters on her own. Disregarding this warning, Nicole agrees to Paolo s request to meet him at a secret location once he s told her that he thinks he knows who the real murderer is. She fails to notice Zappi shadowing her closely. The meeting almost turns into a hostage drama: Nicole gets grabbed by the killer Zappi, but then Paolo comes to her aid unexpectedly and succeeds in overpowering her assailant. When the police arrive at the scene, Paolo has to make his escape yet again before he has a chance to tell Nicole who it is he suspects. Because of his involvement in Milena s death, Martelli is also one of the chief suspects in the spectacular series of murders. Nicole, however, doubts very much that he is guilty. And rightly so, when it turns out that Daniela, the murdered man s wife, had been spending the night with Martelli on the evening that the murder took place. But at this point the murderer strikes again. One evening, Nicole is visited by the woman medium, who, distraught, begs her to help Paolo: she senses that he s in deadly danger in the villa where the murder took place. When the police arrive there, her prophecy turns out to have been absolutely right: Nicole arrives too late to save Paolo s life. Superintendent Avanzo steps up the search for the real murderer, and hears from a Florentine art-dealer that Massimo, the dead man s brother, had secretly been misappropriating valuable paintings from his parents  villa. A few days before Marco s murder, the latter had exposed Massimo as a trickster. When Avanzo is handed a highly incriminating piece of evidence by Severa, the family housekeeper, which destroys Massimo s alibi once and for all, the superintendent has Massimo placed under arrest for suspected murder. Not all is as it seems, however... Nicole s instincts tell her that her search isn t over yet. Among Sandra s papers she finds a letter, in which she discovers that the seventeen-year-old daughter of Severa the family housekeeper died a few months previously. The journalist senses that this was kept secret for reasons that are anything but harmless. She makes one final attempt to unveil the mystery, and follows Severa to the village of Braga, where the housekeeper spends her free time with her son Michele. There, standing next to her daughter s grave, Severa makes an appalling confession: she says that she was the person who murdered Marco. It was an act of revenge against the man who had seduced her pretty daughter and then turned her into a drug-addict. Sandra, her daughter s successor, had surprised the housekeeper shortly after the murder and so she, too, had to be eliminated. As did Paolo, who had begun to suspect her a long time ago. Before Severa manages to kill Nicole, who is the only witness to this confession, her son Michele intervenes. He knew of his mother s crimes, but had kept silent out of love of her. Now he realises that it s his responsibility to avoid any further bloodshed, and he notifies the police. Finally, Nicole is able to close the most horrible chapter of her life. Before she leaves the terrible town, she says goodbye with a heavy heart to Superintendent Avanzo. Who knows what their friendship might have become in some other place, at some other, better time...