In December 1968 two girls - Mary Bell, eleven, and Norma Bell, thirteen (neighbours, but not related) - stood before a criminal court in Newcastle, accused of strangling, within a six-week period, Martin Brown, four years old, and Brian Howe, three. Norma was acquitted. Mary Bell, the younger but infinitely more sophisticated and cooler of the two, was found guilty of manslaughter rather than murder because of 'diminished responsibility' and was sentenced to 'detention' for life. Step by step, the extraordinary murders, the events surrounding them, the alternately bizzare and nonchalant behaviour of the two girls, their brazen offers to help the distraught families of the dead boys, the police work that led to their apprehension, and the trial itself are grippingly re-created in this rare-study of the wanton murder of child by child. What emerges with equal force is the inability of society to anticipate such events and to take adequate steps once disaster has struck.