Forensic psychiatrist Dr Sohom Das diagnoses, treats and rehabilitates mentally ill offenders - or the 'criminally insane' - in prisons and secure hospitals, many of whom have committed serious violence, some even murder. He is also an expert witness, and advises on insanity or diminished responsibility pleas - to either steer the incapacitated, the vulnerable and voiceless away from a lifetime of incarceration towards recovery, or literally let them get away with murder.

In this book, Dr Das tells the untold story of forensic psychiatry during his 15 years as a psychiatric doctor, and what happens when an underfunded institution like this breaks - and how he's learned to live with his mistakes when the worse happens. He also writes very personally and movingly about the abundant tragedy he has encountered in real-life cases, and the human cost of violence caused by mental illness.