A group of refugees cross the Mediterranean Sea from Libya in search of a better life. When they reach shore on the island of Isola Bella, Sicily, they are gunned down in a senseless massacre. Their bodies are found by an Australian tourist, Susan Blackstone, while having her morning swim. She is able to raise the alarm after getting help from two university students, Angela and Aurelio, who are also on the island. After the police arrive she meets Commissario Luca Lombardo who is leading the investigation. He is a man committed to ending the exploitation of refugees. He has recently been in charge of two cases involving human trafficking which have affected him deeply. The discovery of this new crime drives him further in his determination to find out who is behind these shocking deaths. Susan unwittingly finds herself caught up in the murky world of the Mafia and their links to the trafficking of refugees. Several more deaths and a kidnapping leads her to form a close bond with the Commissario as they attempt to bring justice to the dead refugees and prevent more exploitation by local crime families. The investigation takes them from the wealthy, historical town of Taormina, to the busy capital Palermo, on to the town of Bagheria and the seaside village of Santa Flavia, finally ending in a terrifying climax on the island of Levanzo.