In 1965, 18 convicted criminals were sentenced to death for murder – a haunting testimony to the failure of a bold experiment to reform seasoned criminals in a gaol without bars. Right to the end, Daniel Dutton, director of the model penal settlement, could not believe that the men he had befriended and worked so hard to rehabilitate would want to destroy him. Too late he realised the extraordinary hold secret society leaders had over their men. Pulau Senang reconstructs the events that led to the tragedy and the trial, and throws light on a question that has never been answered satisfactorily – Why did the experiment fail?