In this book we will tackle the complex and fascinating topic of psychopathy, one of the most interesting but at the same time controversial mental disorders. Through the recounting of real cases and the most recent studies in the scientific literature, we will try to understand what goes on in the mind of a psychopathic individual. Psychopathy is considered a personality disorder characterized by traits such as emotional coldness, lack of empathy, manipulativeness and antisocial behavior. For a long time it was considered almost a mystery, but today neuroscience has made significant strides in elucidating its biological and neurophysiological mechanisms. Using functional neuroimaging techniques, we have discovered structural and functional differences in brain circuits related to emotional processing and self-awareness. In addition, genetics seems to play an important role in determining the predisposition to develop psychopathic traits. In these pages we will try to shed light on the inside of a psychopathic mind, analyzing its neurobiological and psychological secrets. A fascinating journey into the dark side of the human psyche, to better understand one of the most complex and elusive disorders.