The Fifth Crime tells two interwoven stories. One is the story of an idea whose time has come: the campaign to recognise ecocide - the destruction of the natural world - as an international crime, alongside genocide, crimes against humanity, war crimes and aggression. Born in the shadow of Vietnam, and carried forward by a new generation, it is a legal revolution that seeks to place the protection of nature and the planet at the heart of justice.

The second is a deeply personal journey. Philippe Sands traces his own making as a lawyer: from a childhood in London, through university, to courtrooms and negotiating tables across the world. Along the way come encounters with scientists, politicians, activists, judges and visionaries - figures who reshape his understanding of law and of the responsibilities we owe to one another, and to the Earth itself.

Moving between past and present, private memory and global ecological crisis, Sands explores how international law has long been centred on human interests - and how it might yet evolve to serve the protection of nature. The Fifth Crime is both an education in idealism and a call to action: a book about how change happens, about how ideas can affect consciousness, and about those who dare to think and act differently.