Ronson visits purported psychopaths, as well as psychologists and psychiatrists who have studied them, and meets with Robert D. Hare, the eponymous author of the Hare Psychopathy Checklist, a 20‑part test administered to detect psychopathy. He explores the idea that many corporate and governmental leaders are psychopaths whose actions to others can only be explained by taking that fact into account, and he privately uses the Hare test to determine if he can discern any truth to it.
He meets Toto Constant, who he speculates is a psychopath, corporate leader Albert J. Dunlap, whom the magazine Fast Company speculated was a psychopath, as well as a young man imprisoned in Broadmoor Psychiatric Hospital who claims to be a victim of the psychiatric industry's unfair diagnosis. He also researches unorthodox treatments.
The subject of how journalistic coverage of psychopathology is pursued – and whether that pursuit itself is sociopathic – is also covered.
Ultimately, he raises the question of where the line can be drawn between sanity, insanity, and eccentricity.