Chapter 1 Introduces The Book, Its Aims, And Its Methodology. This Book Explores Two Questions: (i) Why Ordinary People Inform On Others In Repressive Times, Focusing On Emotions As Drivers, And (ii) How, After Those Times End, Law And Politics Should Speak Of, To, And About Informers. The Introductory Chapter Sets Out What We Mean By The Informer And The Role Of (e)motion-namely The Motion Produced By Emotion-in Human Decision-making. It Introduces Our Case-study: Communist Czechoslovakia And Its Secret Police, The Státní Bezpečnost (stb). Our Focus Is On 'everyday Informing' And On The Construction Of Czechoslovak State-society Relations As Interactively Webbed And As Illustrating Both Participatory Dictatorship And Social Engineering. The Source-data We Mostly Rely Upon To Develop Informer File-stories Are The Stb Secret Collaborator Files. This Introduction Therefore Elucidates The Limits And Opportunities Presented By Secret Police Archives As Knowledge Sources-- Provided By Publisher.