Chief Inspector Yiannis Patronas is summoned to an abandoned refugee camp on the Greek island of Chios where he finds the body of a murdered young Syrian woman. His search for her killer leads him first into the labyrinth of Vial, an overcrowded migrant camp, then onto Turkey. The investigation proves to be one of the most challenging of his career as he seeks to understand the migrants and the world they live in and catch the man responsible. When a second Syrian woman is killed, Patronas sends one of his associates into the camp undercover, desperate for information. However, an unspeakable tragedy occurs when she is inadvertently exposed as a police officer. Then one night at the harbor, he boards a Russian trawler and finds crucial evidence in its hold, revealing the scope of what he is up against and forcing him to face an evil beyond his comprehension