Young detective Nicholas Troy is basically a good man, for whom working in homicide is the highest form of police work. But when a woman falls from the construction site for the world's tallest skyscraper, the tortured course of the murder investigation that follows threatens his vocation.

Hampered by politicised managers and incompetent colleagues, Troy fights his way through worlds of wealth and poverty, people-smuggling and prostitution. He has always seen Sydney as a city of sharks, a place where predators lurk beneath the glittering surface. Now he uncovers networks of crime and corruption that pollute the city, reaching into the police force itself.

Finally, the shadowy predator Troy has been chasing turns and comes for him, putting his family at risk. Forced to defend himself with actions he would never have considered before, Troy confronts a moral abyss. He realises it's a long way down.