A large number of difficult patients who self-harm and hear voices, but who are not schizophrenic, are sometimes diagnosed as having a borderline personality disorder, but may often be better understood as suffering from trauma-based dissociative disorder, the most extreme form of which is Multiple Personality/Dissociative Identity Disorder. This is a book of clinical, theoretical and historical importance. Drawing on exciting recent developments in work on trauma and dissociation, Phil Mollon provides a clinically based conceptual model and account of the therapeutic process with patients whose personalities are structured around trauma and pretence. The complexities and hazards of the process are fully considered, as are the problems of Recovered Memory and Pseudomemory. The author illustrates the concepts and process by a detailed account of therapy with MPD/DID, and the specific problem of the perverse sexual abuse of children is dealt with in a chapter on the nature of deep perversion and evil. Trauma and dissociation present challenges to both psychoanalysis and mainstream psychiatry and clinical psychology. Therapists, counsellors and nurses who work within the cognitive or analytic approaches to assessment and treatment will welcome this thoughtful and useful book.